Heat Exhaustion vs Heat Stroke: The Difference That Saves Lives

The man in the July parking lot didn’t collapse dramatically. He just stopped mid-sentence, set down the box he was carrying, and stared at his own car keys as if they belonged to someone else. His coworker thought he was joking. He wasn’t. Ten minutes earlier he’d been sweating and complaining about the heat, annoying, but ordinary. The blank stare was something else entirely.

Every summer, emergency departments see this same story play out: a person who was “just a little overheated” until, suddenly, they weren’t. The gap between heat exhaustion and heat stroke can be minutes wide, and the people best positioned to close it are rarely medical professionals. They’re coworkers, coaches, parents, and neighbors.

The good news is that the distinction isn’t subtle once you know what to look for. It hinges less on how hot someone feels and more on how well their brain is working.

How do I tell if I have heat exhaustion or heat stroke?

Watch the brain, not the sweat. That’s the single most useful rule in all of heat medicine. A person with heat exhaustion feels awful, dizzy, nauseated, weak, drenched, but they can answer questions, follow instructions, and walk to shade with help. A person with heat stroke has crossed a physiological line: their core temperature has climbed to around 104°F (40°C) or beyond, and their nervous system is malfunctioning. Confusion, slurred speech, stumbling, combativeness, seizures, or unconsciousness all point to heat stroke, according to the CDC.

Sign	Heat exhaustion	Heat stroke
Thinking	Clear, though tired or dizzy	Confused, agitated, slurred, or unconscious
Skin	Cool, pale, clammy; heavy sweating	Hot; may be dry or still sweating
Body temperature	May be elevated, below 104°F (40°C)	About 104°F (40°C) or higher
Pulse	Fast and weak	Fast and often pounding
What to do	Cool down, sip fluids, rest	Call 911, cool aggressively, no fluids if confused

One caveat worth taking seriously: you will rarely have a thermometer handy, and an oral reading underestimates core temperature anyway. When the numbers aren’t available, mental status is your thermometer. If the person in front of you can’t hold a normal conversation, treat it as heat stroke and get emergency help. Overreacting to heat exhaustion costs a phone call. Underreacting to heat stroke can cost a life.

What are the first signs of heat exhaustion?

Heat exhaustion announces itself, which is precisely why it’s survivable: the body is still sounding alarms. The earliest signals, per Mayo Clinic and the NHS, tend to arrive in a recognizable cluster:

• Heavy sweating, often more than the situation seems to warrant
• Cool, pale, clammy skin, sometimes with goosebumps despite the heat
• Dizziness or lightheadedness, especially on standing up
• Headache, nausea, and sometimes vomiting
• Muscle cramps, frequently in the calves, thighs, or abdomen
• A fast but weak pulse, and a general sense of being wiped out
• Intense thirst and noticeably darker urine

Notice what’s missing from that list: confusion. A person with heat exhaustion knows something is wrong. They’ll say things like “I feel terrible” or “I need to sit down”, statements that require an intact, self-monitoring brain. That self-awareness is your reassurance, and it’s also fragile.

Timing matters too. Heat exhaustion can build across hours of yard work or a single hard hour on a soccer field, and it can also creep up over several days of a heat wave, particularly in homes without air conditioning. Older adults often experience the slow-burn version, which is easy to mistake for ordinary fatigue. If a hot week has left someone unusually weak, dizzy, or nauseated, don’t chalk it up to age or a bad night’s sleep. The pattern deserves the same response as the athlete’s version: cooling, fluids, and rest, starting now.

Why confusion is the red flag doctors look for

Ask an emergency physician to define heat stroke in one phrase and you’ll usually hear some version of “a hot patient with an altered mind.” The brain earns that starring role because it is exquisitely heat-sensitive. Neurons begin misfiring at core temperatures other organs can still tolerate, which makes mental status the earliest reliable window into what’s happening inside.

The changes can be dramatic or deceptively subtle. Full-blown signs include seizures, unresponsiveness, and collapse. Subtler ones, the kind bystanders talk themselves out of, include irritability out of proportion to the situation, giving strange answers to simple questions, staggering as if drunk, slurred words, or a glassy, vacant look. Coaches sometimes describe an athlete who suddenly “isn’t there,” running the wrong direction or arguing incoherently. Family members of older adults may notice new confusion during a heat wave and assume it’s dementia getting worse. According to Mayo Clinic, any altered mental state or behavior in the setting of heat exposure is a core feature of heat stroke, not an incidental one.

Here’s the practical test worth memorizing: ask the person their name, where they are, and what day it is. Wrong answers, long hesitations, or hostility to the question itself all count as red flags. So does an inability to walk in a straight line. You are not diagnosing anyone: that’s the hospital’s job. You are triaging, and the bar for calling 911 should be low. Confused plus hot equals emergency, every time, until a medical team proves otherwise.

What actually happens inside an overheating body

Your body defends a core temperature near 98.6°F (37°C) with two main tools. The first is dilating blood vessels near the skin, which routes warm blood outward so heat can radiate away: the reason faces flush in summer. The second is sweating, which cools you only when the sweat evaporates. Both tools are managed by the hypothalamus, a thermostat roughly the size of an almond sitting deep in the brain.

Both tools also carry costs. Shunting blood to the skin forces the heart to pump harder and faster to keep the brain and muscles supplied. Sweating drains water and sodium; an adult working hard in the heat can lose more than a liter of sweat per hour. Heat exhaustion is essentially this system running at its limit: the cardiovascular strain and fluid loss produce the dizziness, weakness, racing pulse, and nausea, but the thermostat is still in charge.

Heat stroke is what happens when the thermostat loses. Once core temperature pushes past roughly 104°F (40°C), the damage stops being about fluid and starts being about heat itself. Proteins begin to denature: the same chemistry that turns an egg white opaque in a pan. The gut lining becomes leaky, spilling bacterial products into the bloodstream and triggering a body-wide inflammatory cascade. Kidneys, liver, muscle, and the clotting system can all start to fail in sequence, which is why MedlinePlus classifies heat stroke as a life-threatening emergency. This mechanism explains the urgency: every minute above that threshold is a minute of accumulating cellular damage, and the only treatment that interrupts it is rapid cooling.

How can I treat heat exhaustion?

Heat exhaustion is one of the few conditions where prompt first aid usually resolves the problem completely, if you act rather than push through. The steps, drawn from the NHS and CDC, are refreshingly low-tech:

• Move the person to a cool place, air conditioning if possible, deep shade if not, and stop all activity immediately.
• Have them lie down with feet raised slightly, which helps blood return to the brain and eases dizziness.
• Remove unnecessary clothing: shoes, socks, hats, outer layers.
• Offer cool water or a sports drink, sipped steadily rather than gulped. If cramps are prominent, a drink with electrolytes helps replace the sodium lost in sweat.
• Cool the skin actively: a cool shower, wet cloths or a sponge on the face and neck, cold packs wrapped in cloth at the armpits and groin, and a fan moving air across damp skin.

Then watch the clock. The NHS gives a concrete benchmark worth committing to memory: a person with heat exhaustion should start feeling meaningfully better within 30 minutes of cooling and fluids. If they don’t, or if anything worsens, or confusion appears at any point, you are no longer treating heat exhaustion. Call emergency services.

Two mistakes derail this otherwise simple protocol. The first is negotiating: “I’ll just finish this last row of the garden.” Symptoms are the body’s stop signal, not a suggestion. The second is cooling briefly, feeling somewhat better, and returning to the heat the same day. Recovery takes longer than relief does.

First aid for heat stroke: what to do while the ambulance is coming

Call 911 first. Then cool, fast, and by any means available. Those two actions, in that order, are the entire strategy, and the second one matters more than most people realize. Survival in heat stroke tracks closely with how quickly core temperature comes down, which is why bystander cooling before the ambulance arrives can genuinely change the outcome.

The most effective field method for a young, previously healthy person who collapsed during exertion is cold-water immersion: a tub, a stock tank, a kiddie pool, even a tarp filled with ice water, keeping the head supported above the surface. When immersion isn’t possible, improvise aggressively: move the person to shade or AC, strip excess clothing, douse the skin with water, fan continuously, and pack ice or cold, wet towels against the neck, armpits, and groin, where large blood vessels run close to the surface. Rotate the towels as they warm. Mayo Clinic endorses all of these as bridge measures until emergency care takes over.

Just as important is what not to do. Give nothing by mouth to anyone who is confused, vomiting, or drowsy: a compromised airway plus liquid is a choking hazard. Skip fever-reducing medicines entirely; they work on the brain’s thermostat setting, which isn’t the problem in heat stroke, and they may add strain to a liver and kidneys already under attack. Don’t wrap the person in wet sheets without airflow, which can trap heat. And never leave them alone, even briefly. If they vomit, turn them gently onto their side and keep cooling.

Can heat exhaustion turn into heat stroke?

Yes, and this progression is the reason the distinction saves lives. Heat illness isn’t a set of separate diseases so much as a continuum: heat cramps at the mild end, heat exhaustion in the middle, heat stroke at the catastrophic end. A person can slide along that spectrum in under an hour if the heat exposure continues, and faster still if they’re dehydrated, exerting themselves, or unable to escape the environment.

The tipping point isn’t random. Heat exhaustion means the cooling system is overwhelmed but functioning; the transition to heat stroke happens when that system fails outright. Contributing factors stack up quickly: sweating depletes fluid volume, low volume reduces blood flow to the skin, less skin blood flow means less heat escapes, and core temperature ratchets upward. It’s a feedback loop, and feedback loops accelerate.

This is why the NHS’s 30-minute rule is such a valuable piece of public health guidance. It converts a vague worry, “is this getting worse?”, into a measurable checkpoint. Start cooling, note the time, and reassess in half an hour. Improvement means you’re on the right track; stall or decline means escalate. Between checkpoints, watch specifically for the transition markers: any new confusion, speech changes, unsteadiness, a body that feels hot to your touch, vomiting that prevents drinking, or fainting. Any one of these ends the wait-and-see period immediately.

The reverse question matters too: heat stroke does not require a heat-exhaustion warm-up. In hard exertion or extreme conditions, some people go from apparently fine to critically ill with little in between, which is why buddies, coaches, and coworkers should watch each other in the heat, not just themselves.

Classic vs. exertional heat stroke, and why 'dry skin' misleads people

Generations of first-aid posters taught that heat stroke means “hot, red, dry skin,” and that half-truth still gets people hurt. The dry-skin picture describes only one of heat stroke’s two forms.

Classic (non-exertional) heat stroke develops over hours or days of environmental heat, typically during heat waves. Its usual victims are older adults, people with chronic illnesses, and those without air conditioning, people whose sweating capacity is limited to begin with or has been exhausted by prolonged exposure. In this group, skin frequently is hot and dry, and the danger often builds quietly indoors. During major heat waves, a large share of deaths occur in exactly this population, frequently in their own homes.

Exertional heat stroke is a different animal. It strikes during intense physical activity, athletes in preseason training, military recruits, roofers, landscapers, warehouse and agricultural workers, and it can develop within an hour. Because the person’s sweat glands are young and firing at full capacity, they are very often still drenched in sweat at the moment their core temperature crosses the critical line. A soaked jersey proves nothing about safety. Mayo Clinic explicitly notes that in heat stroke brought on by exertion, the skin may feel moist.

The practical takeaway is blunt: strike “dry skin” from your mental checklist as a requirement. It’s a supporting clue in classic heat stroke, nothing more. The reliable signs, the ones present in both forms, are dangerously hot skin and a brain that isn’t working right. If you wait for the sweating to stop before calling for help, you may wait too long.

Who is most at risk in the heat?

Anyone can develop heat illness, but risk is far from evenly distributed. The CDC and MedlinePlus consistently flag several groups:

• Adults 65 and older. Aging blunts the thirst signal, reduces sweating capacity, and slows the cardiovascular adjustments that shed heat. Many older adults also feel heat less acutely, so the body’s own warning system is quieter.
• Infants and young children. Small bodies heat up faster, produce relatively more metabolic heat, and depend entirely on adults for water, shade, and escape. A parked car is uniquely lethal: interior temperatures can climb roughly 20°F in the first 10 minutes, even with windows cracked.
• People with chronic conditionsheart disease, kidney disease, diabetes, obesity, and some neurological conditions all reduce heat tolerance or complicate the body’s response.
• People taking certain medicines. Some medications used for blood pressure, mental health conditions, allergies, and bladder problems can reduce sweating, alter fluid balance, or blunt thirst. Rather than memorizing categories, ask a pharmacist directly whether anything you take affects your heat tolerance: it’s a five-minute conversation worth having every summer.
• Outdoor workers and athletes, especially during the first one to two weeks of a new season or job, before the body has acclimatized.
• People without reliable air conditioning, who face cumulative exposure with no overnight recovery. Nights that stay hot are particularly dangerous because the body never gets a break.

Alcohol deserves its own mention: it promotes fluid loss and impairs both judgment and the perception of heat, a combination that shows up repeatedly in heat stroke cases.

Does humidity really matter that much?

More than temperature alone, in many situations. Sweat cools you only by evaporating: the phase change from liquid to vapor is what pulls heat off your skin. Humid air is already loaded with water vapor, so sweat beads, drips, and soaks your shirt instead of evaporating. You lose the fluid without gaining the cooling, which is the worst of both worlds.

This is why 90°F in Phoenix and 90°F in New Orleans are two very different afternoons, and why forecasters lean on the heat index: a “feels like” number combining temperature and relative humidity. The differences aren’t trivial. At 90°F with 40% humidity, the heat index sits around 91°F; push humidity to 70% and the same air temperature feels like roughly 105°F, well into the range where heat illness becomes likely with prolonged exposure or exertion. Direct sunlight can add up to about 15°F on top of the published index, which is measured in shade.

Humidity also sabotages your intuition. On a dry day, evaporation is so efficient you may not notice how much you’re sweating, fluid loss sneaks up on you. On a humid day, cooling fails even though you’re visibly drenched, and people misread all that sweat as proof the system is working. Neither perception is trustworthy; the heat index is.

A practical habit: check the heat index, not just the temperature, before outdoor work or exercise, and shift strenuous activity to early morning when both numbers are lowest. When the heat index passes about 103°F, the CDC’s guidance moves from caution to danger, and rescheduling stops being an overreaction and starts being the evidence-based choice.

How many days does it take to recover?

The honest answer splits sharply depending on which condition you had, and the gap between the two recovery timelines is itself a good illustration of how different these illnesses are.

Heat exhaustion, treated promptly, usually resolves within 24 to 48 hours. Expect to feel washed out for a day or so: lingering fatigue, a dull headache, reduced appetite. Rest in a cool environment, keep drinking fluids, and stay out of the heat entirely for at least the next day. Returning to strenuous outdoor activity the same afternoon is how a near-miss becomes a hospital visit, because your heat tolerance is temporarily lowered even after symptoms fade.

Heat stroke is a different story, and anyone promising a tidy number of days isn’t being straight with you. Recovery begins in a hospital, where the priorities are rapid cooling and monitoring for organ injury, kidneys, liver, muscle, and the clotting system are all vulnerable. What follows depends on how high the temperature climbed and how long it stayed there. Some people recover fully over a few weeks; others deal with lingering effects, including a measurably reduced heat tolerance that can persist for months. Research on exertional heat stroke in athletes and military personnel suggests thermoregulation can remain impaired well after a person feels subjectively normal, which is why sports medicine programs use gradual, supervised return-to-activity protocols rather than a fixed date.

Whatever your situation, the clinician who treated you should set the timeline for returning to heat, exercise, and work. One heat stroke also raises your risk of another, so treat your first as a permanent line item in your medical history, one worth mentioning at future appointments.

What about heat cramps and heat rash?

Two milder heat conditions round out the family, and both are worth recognizing, partly for their own sake, and partly because heat cramps in particular can be an early tremor before a bigger quake.

Heat cramps are painful, involuntary muscle spasms, typically in the calves, thighs, shoulders, or abdomen, that strike during or after heavy sweating. The mechanism is a salt problem more than a water problem: profuse sweating drains sodium, and muscles bathed in low-sodium fluid become electrically irritable. That’s why plain water sometimes fails to fix cramps and can even feel like it makes them worse. The CDC’s advice: stop activity, move somewhere cool, sip water or a sports drink, and wait for the cramps to pass before resuming. If cramps last longer than an hour, or you have a heart condition or follow a low-sodium diet, check in with a medical professional rather than pushing through. Treat cramps as a warning shot: the same conditions that produced them can produce heat exhaustion within the hour.

Heat rash (prickly heat) is more nuisance than danger: clusters of small red bumps or tiny blisters, usually on the neck, chest, groin, or in skin folds, caused by blocked sweat ducts. Babies are especially prone. The fix is to keep the area cool and dry, light clothing, air conditioning, powder rather than heavy ointments, which can block ducts further. It typically clears on its own once you’re out of the heat.

Neither condition is an emergency. Both are your body filing a formal complaint about the conditions, and both deserve a response: cool down, and reassess the day’s plans.

When should you see a doctor?

Some heat situations call for a phone, not a water bottle. Call 911 immediately, do not drive the person yourself if help is available, for any of the following:

• Confusion, slurred speech, strange behavior, or unresponsiveness in someone who has been in the heat
• Fainting or a seizure
• A measured temperature of 104°F (40°C) or higher
• Skin that feels hot to the touch alongside any of the above
• Symptoms of heat exhaustion that haven’t improved after 30 minutes of active cooling and fluids: the NHS threshold for treating the situation as heatstroke

Seek same-day medical care, urgent care or your regular clinician, for situations that are serious but not immediately life-threatening: vomiting that prevents keeping fluids down, symptoms that improve and then return, heat cramps lasting more than an hour, very dark urine or a marked drop in urination (possible signs of dehydration or kidney strain), or heat exhaustion in someone who is pregnant, over 65, or living with heart or kidney disease. These groups have less physiological margin, and “probably fine” is a riskier bet.

Follow-up care matters more than people expect. Anyone hospitalized for heat stroke needs scheduled follow-up to check organ recovery and to plan a safe return to heat and activity. And if you had heat exhaustion that seemed to come out of nowhere, mild conditions, modest exertion, mention it at your next appointment. Occasionally an unexpectedly poor heat tolerance is the first visible sign of a medication effect or an underlying condition worth investigating, per Mayo Clinic.

How to prevent heat illness before it starts

Prevention is unglamorous and remarkably effective. A handful of habits, applied consistently, prevents the overwhelming majority of heat emergencies:

• Respect acclimatization. The body genuinely adapts to heat, sweating starts earlier, becomes more efficient, and wastes less salt, but the process takes one to two weeks of gradually increasing exposure. The first heat wave of the season and the first week of a new outdoor job are statistically the most dangerous windows. Ramp up; don’t dive in.
• Drink on a schedule, not on thirst. Thirst lags behind actual fluid needs, and the lag widens with age. During sustained heat or work, sip regularly and let urine color be your gauge, pale yellow is the target. For heavy sweating beyond an hour, include some electrolytes.
• Time the day around the heat. Shift strenuous tasks to early morning, take shade breaks before you feel you need them, and treat the heat index, not the raw temperature, as your planning number.
• Dress for evaporation: lightweight, light-colored, loose-fitting clothing and a wide-brimmed hat.
• Never leave anyone in a parked carnot children, not older adults, not pets, not “for a minute.” Interior temperatures rise about 20°F in the first 10 minutes.
• Check on people. During heat waves, a daily call or knock on the door of an older neighbor or relative living alone is one of the most effective public health interventions there is. Many classic heat stroke deaths happen quietly, indoors, to people no one checked on.

If home cooling isn’t reliable, even a few hours a day in an air-conditioned library, mall, or community cooling center measurably lowers risk, according to the CDC.

Three heat myths worth retiring

Myth one: “If you’re still sweating, you’re fine.” Exertional heat stroke routinely strikes people who are drenched in sweat. Sweating tells you the glands are working; it says nothing about whether cooling is keeping pace with heat production. On a humid day, or during hard exertion, it often isn’t. Judge by mental status and how the skin feels, dangerously hot skin is alarming whether it’s wet or dry.

Myth two: “Fever-reducing medicine will bring the temperature down.” It won’t, and the reason is mechanistic. Fever is the brain deliberately raising its own thermostat setting in response to infection; fever reducers work by resetting that thermostat. In heat stroke, the thermostat isn’t set high: it’s been overwhelmed by external heat and internal heat production. There’s nothing for the medicine to reset, and it may add stress to organs already injured. The only treatments that lower a heat stroke temperature are physical: water, ice, airflow, and immersion.

Myth three: “Thirst will tell me when to drink.” Thirst is a lagging indicator, by the time it registers, you’re already behind on fluids, and the signal weakens substantially with age. Older adults can be meaningfully dehydrated without feeling thirsty at all, which helps explain why they’re overrepresented in heat wave casualties. During sustained heat exposure, drink on a schedule and watch urine color instead.

Each of these myths shares a common flaw: it substitutes a comforting signal for the ones that actually matter. The evidence keeps pointing back to the same short list, brain function, skin temperature, and the clock. Trust those, and you’ll make the right call.

Frequently asked questions

How do I tell if I have heat exhaustion or heat stroke?

Check thinking first. Heat exhaustion causes heavy sweating, clammy skin, dizziness, nausea, and weakness, but the person remains alert and can answer questions normally. Heat stroke involves a body temperature around 104°F (40°C) or higher plus brain dysfunction, confusion, slurred speech, stumbling, seizures, or unconsciousness. If someone who has been in the heat can’t hold a normal conversation, treat it as heat stroke and call 911 immediately.

What are the first signs of heat exhaustion?

Heavy sweating with cool, pale, clammy skin is the classic opener, typically joined by dizziness (especially on standing), headache, nausea, muscle cramps, intense thirst, dark urine, and a fast but weak pulse. The person feels terrible but thinks clearly: that self-awareness is the reassuring feature. Symptoms can build over one hard hour outdoors or creep up across several days of a heat wave, particularly in homes without air conditioning.

How can I treat heat exhaustion at home?

Move to a cool place, stop all activity, and lie down with feet slightly raised. Remove excess clothing, sip cool water or a sports drink, and cool the skin with wet cloths, a cool shower, a fan, or cold packs at the armpits and groin. Most people improve within 30 minutes. If symptoms persist beyond that, worsen, or any confusion appears, call emergency services: you may be dealing with heat stroke.

How many days does it take to recover from heat stroke?

There’s no fixed number, and that honesty matters. Recovery starts in a hospital and depends on how high the temperature rose and for how long. Some people recover over a few weeks; others have lingering effects, and reduced heat tolerance can persist for months. Athletes typically follow gradual, supervised return-to-activity protocols. The clinician who treated you should set your specific timeline for returning to heat, exercise, and work.

Can you have heat stroke and still be sweating?

Yes, absolutely. Exertional heat stroke: the kind that strikes athletes, soldiers, and outdoor workers during intense activity, very often occurs while the person is still drenched in sweat, because their sweat glands are working at full capacity even as core temperature crosses the danger line. The ‘hot, dry skin’ picture applies mainly to classic heat stroke in older adults during heat waves. Never wait for sweating to stop before calling for help.

Should I give water to someone with heat stroke?

Not if they’re confused, drowsy, vomiting, or unconscious, liquid given to someone who can’t protect their airway is a choking hazard. For suspected heat stroke, the priorities are calling 911 and cooling the body externally: cold-water immersion if possible, or dousing the skin, fanning, and placing ice packs at the neck, armpits, and groin. Fluids by mouth are appropriate only for fully alert people with milder heat exhaustion.

Do fever-reducing medicines help with heat stroke?

No. Fever reducers work by resetting the brain’s thermostat, which is deliberately raised during infection. In heat stroke, the thermostat isn’t set high: it has been overwhelmed by heat, so there’s nothing for the medicine to act on, and it may add strain to a liver and kidneys already under stress. The only effective treatments are physical cooling: water, ice, moving air, and cold-water immersion, plus emergency medical care.

Can heat exhaustion happen indoors?

Yes, and indoor cases are common during heat waves, especially in homes without air conditioning. Classic heat stroke in older adults frequently develops indoors over several days, as heat accumulates and nights stay too warm for the body to recover. Warning signs can look like ordinary fatigue, weakness, dizziness, nausea, new confusion. Daily check-ins on older neighbors and relatives during heat waves are a genuinely effective safeguard, and a few hours in any air-conditioned space lowers risk.

What temperature counts as heat stroke?

A core body temperature of about 104°F (40°C) or higher, combined with signs of nervous system dysfunction such as confusion or unconsciousness, defines heat stroke. In practice you rarely have an accurate thermometer available, and oral readings underestimate core temperature anyway. That’s why first-aid guidance emphasizes mental status: a person who is hot to the touch and not thinking clearly should be treated as having heat stroke regardless of any number you can measure.

How long should I wait before exercising again after heat exhaustion?

Stay out of the heat entirely for at least 24 to 48 hours and until all symptoms have fully resolved, because your heat tolerance is temporarily lowered even after you feel better. When you return, ease back in with shorter, less intense sessions in cooler parts of the day and extra fluids. If your heat exhaustion arose from surprisingly mild conditions, mention it to your clinician first, occasionally poor heat tolerance signals a medication effect or underlying condition.

References

• NHS: Heat Exhaustion and Heatstroke
• MedlinePlus: Heat Illness

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.