How long does heat exhaustion last?

You may experience heat exhaustion if your body does not have enough water and salt. This can occur if you are spending a long time outdoors in the sun and are sweating a lot. It is often milder than heat stroke and may develop several days after your initial exposure to the sun.

If you are experiencing heat exhaustion, you’ll typically start to feel better after 30 minutes to 1 hour. If your symptoms do not disappear or you do not cool down after this time, seek medical attention.  

What are the symptoms of heat exhaustion?

Heat exhaustion happens when your body gets too hot. This excess heat can damage your organs.

According to the Centers for Disease Control and Prevention (CDC), certain factors will put you more at risk of experiencing heat exhaustion.

These include:

• being an older adult
• having high blood pressure (hypertension)
• frequently working in a hot environment

Symptoms that occur as a result of heat exhaustion or heat stroke are serious if you do not address them quickly. The first symptom you may notice is likely to be muscle cramping. These muscle cramps are a response to the low levels of salt that heat exhaustion causes.

You may also experience a quickening pulse, which can cause you to feel like you cannot take any deep breaths.

Symptoms to look for if you suspect you are experiencing heat exhaustion include:

• headaches
• extreme thirst
• not urinating frequently
• dark urine
• nausea
• clammy skin
• fainting
• muscle cramps
• dizziness
• extreme sweating
• weakness
• irritability
• very warm body temperature

What is the typical duration of heat exhaustion?

If you are experiencing heat exhaustion, you should typically start to feel better after 30 minutes to 1 hour. If your symptoms do not disappear or you do not cool down after this time, seek medical attention.  

Prolonged symptoms from heat exhaustion can put you at risk of a medical emergency, as it may progress into heat stroke.

Symptoms of heat stroke include:

• a very high body temperature
• a fast heartbeat
• seizure
• loss of consciousness (passing out)
• hot and red skin
• not sweating
• confusion
• dry or damp skin

If you think you may be experiencing heatstroke, it is vital that you seek medical help immediately.

What factors can affect recovery time?

Several factors can increase your chance of developing heat-related illnesses like heat exhaustion. These factors can also increase your risk of experiencing prolonged symptoms of heat exhaustion or more severe symptoms.

These include:

• being a child below 4 years of age
• being 65 years of age or more
• already feeling unwell
• consuming alcohol in hot conditions
• having overweight

Taking certain medications can also cause you to be at an increased risk of experiencing heat exhaustion. These include:

• antihistamines, such as diphenhydramine (Benadryl)
• anticholinergics, such as atropine, diphenoxylate (Lomotil), and benztropine (Cogentin)
• calcium channel blockers, such as amlodipine (Norvasc) and diltiazem (Cardizem
• diuretics, such as bumetanide (Bumex)

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Treatment options for heat exhaustion

Treatment for heat exhaustion should always start with moving into the shade, where the temperature is cool.

You can then take the following steps:

• loosen your clothing
• drink water slowly
• place damp cloths onto your skin
• take a cool bath

If you need medical treatment, this will typically involve intravenous electrolytes, which are a mixture of minerals that you lose as you sweat.

When should you seek medical support?

If you take the previous steps as soon as you notice symptoms of heat exhaustion, you should start to feel better within 1 hour.

If you still experience symptoms after an hour of addressing them, seek medical help. It is also important to seek medical help if your symptoms get worse, even if you notice this within 1 hour.

Throwing up is a sign of severe illness. If you vomit, you must seek emergency medical attention.

Summary

Heat exhaustion can occur if you spend too long in the sun and do not keep yourself hydrated. It can result from a loss of minerals and salts in your body due to excess sweating.

You can help your body recover by moving into a cool area and drinking water. After 30 minutes, your symptoms should start to reduce.

Heat exhaustion can progress into heat stroke. If you still experience symptoms after 1 hour and have tried methods of cooling down, such as sipping water and using wet cloths, seek medical attention.

You should also get help if your symptoms get worse or you begin to vomit.