Heat Exhaustion and Heatstroke: Complete Treatment Guide

Heat exhaustion and heatstroke sit on the same spectrum, but the treatments are not interchangeable. Heat exhaustion can almost always be handled at home with rest, cooling, and fluids. Heatstroke is a medical emergency where every minute of delay raises the risk of organ damage and death. This guide walks through both — what to do in the first minutes, what to do in the next hour, and what to escalate.

This is a practical guide, not a substitute for emergency services. If you suspect heatstroke, call 911 (or your local emergency number) first and start cooling immediately while you wait.

Step zero: figure out which one you are dealing with

Before you treat anything, you have to make a quick triage call. The single most useful question is whether the person's mind is intact.

A person who is sweaty, drained, headachy, and miserable but knows their name, the date, and where they are has heat exhaustion. The cooling system is overloaded but still working.

A person who is confused, slurring, agitated, drowsy, staggering, vomiting repeatedly, or unconscious in a hot environment has heatstroke until proven otherwise. The cooling system has failed and the brain is being affected. You do not have time to wait for a thermometer.

If you cannot decide — assume heatstroke. The treatments for heat exhaustion are a subset of what you would do for heatstroke, so over-treating heat exhaustion costs you nothing while under-treating heatstroke can be fatal.

Treating heat exhaustion: the home plan

Heat exhaustion is uncomfortable but rarely dangerous if treated early and respected.

First five minutes

Stop the exposure. Move the person out of the sun, out of the heat, and into the coolest space available — air conditioning is best, deep shade with airflow is acceptable, a parked vehicle without air conditioning is not.

Loosen or remove restrictive clothing. Belts, tight collars, jackets, anything that traps heat or limits sweating. If a hat is trapping head heat, take it off. Get any heavy gear (vests, pads, helmets) off the body.

Lie the person down with their feet slightly elevated. This helps blood return from the extremities and supports blood pressure. If they feel lightheaded sitting up, keep them lying down.

First fifteen minutes

Start cooling the skin. Wet cloths to the face, neck, chest, and forearms. A small fan moving air across damp skin pulls heat out fast. Cold packs or bags of frozen vegetables wrapped in a thin cloth can go to the neck, armpits, and groin where major blood vessels run close to the surface.

Begin fluid replacement. Sip — do not chug — water, an electrolyte drink, or a sports drink. Cold liquids feel best and are absorbed slightly faster, but lukewarm is fine if cold is not available. If the person is nauseated, slow down. Sips every minute or two work better than gulps that come back up.

Skip caffeine and alcohol. Both interfere with hydration and recovery.

First hour

Watch the trajectory. After 15 to 30 minutes of rest, cooling, and sips, the person should be feeling better. Headache easing, nausea subsiding, alertness improving, sweating reducing as the body catches up. If they are getting better, you are on the right track.

If they are not improving, or are getting worse — confusion appearing, vomiting starting, sweating slowing instead of normalizing — stop treating it as heat exhaustion and treat as heatstroke.

If they fully recover within an hour, the day's heat exposure is over. Do not let them go back outside, return to work, or resume training. The body is more vulnerable to a second episode in the recovery window.

The next 24 hours

Continued rest. Cool environment. Fluids and a normal meal when nausea passes. Sleep tends to be restorative. Most people are back to normal within a day. If symptoms persist past 24 hours, see a clinician — there may be an underlying issue that complicated the response.

Treating heatstroke: the emergency plan

Heatstroke treatment is built on one principle: cool the core as fast as you safely can, while medical help is on the way.

The first action: call

Call 911 (or your country's emergency number) before doing anything else. State clearly that you suspect heatstroke and give the location. The dispatcher may stay on the line and guide you through the next steps.

If you are alone with the person, put your phone on speaker so you can keep your hands free for cooling.

The first minute: stop the exposure

Get the person out of the heat. Indoors and air-conditioned is best. Shade with airflow is the next best. If you cannot move them, create shade — a tarp, a blanket strung over branches, anything to block direct sun.

Strip outer clothing down to the minimum. Remove gear, helmets, vests. The goal is maximum skin exposure for cooling.

The first five minutes: aggressive cooling

This is the part that determines outcome. The most effective method available is the one that gets core temperature down fastest.

In rough order of effectiveness:

• Cold water immersion. A tub, kiddie pool, large cooler, or stock tank filled with cold water and ice. Submerge the body up to the neck. This is the gold standard for exertional heatstroke and is dramatically faster than any other method.
• Cold water dousing. If immersion is not possible, pour buckets of cold water over the body continuously while fanning hard. Wet skin plus moving air pulls a great deal of heat.
• Wet sheets and fans. Wrap the person in wet sheets or towels, keep them soaked with cold water, and run fans across the entire body.
• Ice packs to neck, armpits, and groin. Less effective alone but a useful add-on to any of the above.

Do not stop to wait for the ambulance to start cooling. Cooling now and continuing through transport is the protocol.

What not to do

Do not give fluids by mouth to anyone who is confused, vomiting, or not fully alert. They can aspirate. IV fluids are for the medical responders.

Do not use rubbing alcohol on the skin. It can be absorbed in dangerous amounts and the cooling effect is less than plain water.

Do not give fever-reducing medications like acetaminophen or ibuprofen. They do not work on heatstroke (this is not a fever from infection — it is a failure of thermoregulation) and can stress the kidneys and liver, which are already at risk.

Do not assume the person is fine because they "perked up." Apparent improvement after early cooling can be temporary, and the underlying organ stress may not be visible without lab work. Heatstroke needs hospital evaluation even when the patient looks better.

When help arrives

Hand off cleanly. Tell the responders what time symptoms started, what you have done, the person's age, any medications they take, any known medical conditions, and any current temperature reading you took. Stay out of the way but stay nearby in case they need more information.

After the immediate emergency

Heatstroke survivors are typically admitted for observation and lab work. The kidneys, liver, and clotting system are checked for damage. Muscle breakdown (rhabdomyolysis) is a common complication and is treated with IV fluids. Some patients need ICU care for a few days.

Recovery from heatstroke is not a quick process. Heat tolerance is reduced for weeks to months, sometimes permanently. Returning to training or heavy heat exposure should be supervised by a clinician familiar with the case, with gradual reintroduction.

The risk of a second heatstroke is meaningfully higher in someone who has already had one. Long-term prevention — acclimation, hydration, avoidance of heavy exertion in extreme heat — becomes a year-round habit.

Special situations

Children

Children heat up faster than adults and have less ability to dissipate heat. Treat any heat illness in a child as more serious than it would be in an adult, and lower your threshold for calling 911. Never use ice baths with small children without medical supervision — they can over-cool quickly.

Older adults

Most classic heatstroke cases are in adults over 65 in homes without adequate cooling during heat waves. Treatment is the same in principle — call 911, cool aggressively — but be cautious with cold water immersion in someone with heart disease. Wet sheets, fans, and ice packs are gentler and still effective. Bring the person somewhere cool and call for help; do not try to manage classic heatstroke at home.

Athletes and outdoor workers

Exertional heatstroke can develop in minutes in young, fit people. The protocol on the field or job site is "cool first, transport second." Cold water immersion at the site of collapse, before transport, is associated with the best outcomes. Sports medicine and occupational health programs increasingly carry stocked cooling tubs for exactly this reason.

People on medications

Diuretics, beta-blockers, antihistamines, antidepressants, antipsychotics, and stimulants all interfere with heat tolerance in different ways. People on these medications should be treated more aggressively at the heat-exhaustion stage, since their margin to heatstroke is smaller. Mention current medications to responders.

Prevention is part of treatment

The treatment for the next episode begins the moment the current one is resolved. Hydration habits, acclimation strategies, scheduling work or training around the worst hours, indoor cooling, and recognizing the early signs all reduce the chance of a repeat.

For people who already track migraines or other weather-sensitive symptoms, layering temperature and humidity onto the same record makes hot stretches predictable. Pressure Pal can sit alongside a temperature log so you go into a heat wave knowing which days are likely to be hard, and you can plan to be indoors during the worst windows.

Bottom line

Heat exhaustion and heatstroke are two stops on the same spectrum, but the treatments diverge sharply. Heat exhaustion is rest, cool, fluids, and patience. Heatstroke is 911 and aggressive cooling, immediately, without waiting for the ambulance. The triage decision turns on mental status — a clear mind in a sweaty body is heat exhaustion, a confused mind in a hot body is heatstroke. When in doubt, treat as heatstroke and start cooling. The cost of over-treating heat exhaustion is small. The cost of under-treating heatstroke can be a life.