How long does heat exhaustion last: an outdoor worker in a safety vest struggles with the heat

Summer is almost here again. And while that means sunny days down at the lake or out on the trails, it also means that the risk of heat-related illness is significantly elevated.

Heat exhaustion is particularly common in high temperatures and during heat waves, though it can occur at any time of year. Heat exhaustion symptoms typically last 30 minutes or less when treated promptly. Complete recovery may take anywhere from 24 to 48 hours. To shorten the duration of heat exhaustion, drink plenty of fluids and seek out a cool place to rest and recover.

And for people with underlying conditions or those who live in hot climates, heat exhaustion can occur more frequently.

If you're wondering just how long does heat exhaustion last and what risk factors increase the probability of getting heat exhaustion, use these tips to understand the condition and learn what you can do to prevent it.

What Is Heat Exhaustion?

How long does heat exhaustion last: A man cools down in front of a fan

Heat exhaustion is a condition that occurs when the human body is unable to cool itself down and becomes dehydrated. There are two types of heat exhaustion: water depletion, which occurs when the body doesn’t have enough water, and salt depletion, which occurs when the body has low levels of electrolytes. The Center for Disease Control (CDC) categorizes heat exhaustion as one of several heat-related illnesses, including heat rash, sunburn, heat cramps, and heatstroke.

Many people confuse heat exhaustion with heat stroke or think they mean the same thing. While the conditions are similar, heatstroke is a heat illness characterized by body temperatures over 103 degrees Fahrenheit. Heatstroke, or hyperthermia, is much more severe than heat exhaustion as it taxes vital organs and can cause brain damage or death.

Heat exhaustion, on the other hand, is a mild to moderate condition that can easily be remedied with fluids, electrolytes, and adjustments when it comes to exercise. Body temperatures typically don’t rise above 103 degrees Fahrenheit and there are generally no effects on the body’s organs. 

If heat exhaustion or dehydration isn’t treated promptly, especially in young children, it may lead to heatstroke. Other complications include kidney and liver injury, arrhythmias, and rhabdomyolysis — a condition that can lead to kidney failure. Read on to find out more about the main causes and symptoms of heat exhaustion.

Main Causes of Heat Exhaustion

How long does heat exhaustion last: A fire fighter walks through a brush fire

Heat exhaustion is a heat-related illness that can be caused by a variety of factors. The most common causes of heat exhaustion include strenuous physical activity in a hot environment, and hot and humid weather. Humidity levels over 60% can also increase the risk of heat exhaustion. 

The body naturally cools itself down by sweating. To do this, the body pumps blood cells to the skin’s surface, where dry outside air absorbs the moisture from the skin’s sweat, reducing heat. In hot weather conditions with high temperatures and high humidity, the body isn’t able to cool off as quickly because the moist air doesn’t absorb sweat as well. 

To make things worse, dehydration can make it more difficult for the body to produce sweat and cool off. It’s no surprise then that if you’re doing a hard workout and not drinking enough fluids, the risk of heat exhaustion increases. 

There are other risk factors that can increase the probability of heat exhaustion. People who suffer from health conditions like diabetes and hyperglycemia are much more likely to develop dehydration and heat exhaustion. Smokers and those who use drugs or drink excessively are also more prone to heat exhaustion. 

This heat illness is more pronounced in people who are over 65 and in young children below the age of four. Taking certain medications including some allergy treatments and blood pressure medications can also increase the chance of developing heat exhaustion.

Symptoms of Heat Exhaustion

How long does heat exhaustion last: an athlete experience heat exhaustion steadies himself against a wall

There are many warning signs of heat exhaustion. Initially, you may feel dehydrated or thirsty. As the heat exhaustion takes hold, you may start to feel hot, clammy, and dizzy. 

Here are some of the main symptoms of heat exhaustion to look out for:

  • Fainting
  • Light-headedness
  • Fatigue or low energy
  • Irritability
  • Headache
  • Pale, cold, or clammy skin
  • Excessive sweating
  • Rapid or irregular heartbeat
  • Low blood pressure
  • Rise in internal body temperature
  • Dark urine (an indication of dehydration)
  • Muscle cramps
  • Nausea or vomiting
  • Shallow breathing
  • Red or flushed facial skin that feels hot

How Long Does Heat Exhaustion Last

If your heat exhaustion symptoms do not improve within an hour, get medical help from a local facility. Severe cases of heat exhaustion may need to be treated by administering fluids and electrolytes through an IV.

How To Treat and Prevent Heat Exhaustion

How long does heat exhaustion last: A woman drinks an oral rehydration solution

In most cases, heat exhaustion symptoms will be mild to moderate and can be treated at home. If you think you have heat exhaustion and are throwing up or have symptoms that last more than one hour, seek medical help immediately. 

If your symptoms progress to heat stroke — especially if you have an internal body temperature of 103 degrees Fahrenheit or higher — this is a sign of a medical emergency and you should seek medical attention immediately. Keep an eye out for flushed skin, vomiting, and difficulty processing information or controlling behavior as these are all signs of heat stroke. The key indicator of heat stroke instead of heat exhaustion is a body temperature over 103 degrees Fahrenheit.

Sometimes, medications or underlying issues can contribute to heat exhaustion. If you find that you have regular heat exhaustion episodes, you may want to get medical advice from your physician to find better ways to manage your health. 

Fortunately, making a few lifestyle adjustments and remembering to drink plenty of water can help you avoid most heat exhaustion incidents. Here are other ways you can prevent heat exhaustion, plus tips on what to do if you experience the condition.

Drink Plenty of Fluids, Especially ORS

The easiest thing you can do to prevent and treat heat exhaustion is to drink fluids. Try to drink about one liter of an oral rehydration solution (ORS) every hour. If an ORS is unavailable, make sure that what you are consuming doesn’t have too much sugar or too little salt. 

Our ORS sticks are a great, convenient way to relieve dehydration. One stick of DripDrop ORS contains a precise ratio of sodium, glucose, and electrolytes like potassium, zinc, and magnesium to help relieve dehydration fast. People who need to work hard regardless of the weather, like athletes, the military, and firefighters, rely on DripDrop ORS.

Wear Lightweight Clothing

As you dress for physical activity, consider wearing lightweight, loose-fitting clothing. Lightweight clothes tend to be less hot and a loose fit allows the body to sweat and release heat more efficiently than tight clothes. If you’re out and start experiencing symptoms of heat exhaustion, remove excess articles of clothing and any clothes that are tight-fitting.

Cool Off

Treating heat exhaustion is all about reducing heat and increasing fluid intake. At the first signs of heat exhaustion, try taking a cool shower or hop in an ice bath with cold water. In more severe situations, you can place ice packs under your armpits or on your neck and chest. These areas of the body have large blood vessels near the skin’s surface, which can help you cool off faster than if you place the ice elsewhere. You can also prevent symptoms by wearing a cool, wet shirt or by draping a cooling towel around your neck.

Time Your Outdoor Activities

One of the best methods for heat exhaustion prevention is timing your outdoor activities. Limit strenuous activity during the hottest times of the day — especially between the hours of noon and 4 p.m. Try to exercise outdoors in the early morning or late evening hours. If possible, avoid hard physical labor and exercise outdoors during extreme heat or a heatwave.

There are also tools you can use to plan your outdoor activities. The Weather Channel’s Heat Index chart combines temperature with humidity levels to show you how hot it feels. The heat index chart uses colors to highlight when to use caution and which conditions present danger or extreme danger. 

You can also use the National Oceanic and Atmospheric Administration’s (NOAA) Heat Calculator to plug in the temperature and humidity in your area to find the heat index number at specific times. If the number lands in a higher danger category, avoid outdoor activities until things improve.

Treat Heat Exhaustion With Dehydration Relief Fast

A raspberry, blackberry, strawberry, and cherry represent some of the flavors of DripDrop ORS

If you’re not already convinced to make DripDrop ORS part of your protocol to prevent heat exhaustion, we offer a convenient, low-risk trial size

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