Know the Difference Between Heat Exhaustion and Heatstroke
With record heat waves in the Pacific Northwest, it is important not only to stay relatively cool, but also to actively avoid heat exhaustion and more severe heatstroke. Knowing the signs of both can help protect you, your friends, and family.
Heatstroke is a serious condition that can lead to seizures, organ failure, and more. Before heatstroke, you will experience a milder condition called heat exhaustion. Both conditions occur when the body is overheated. Usually our bodies try to cool us down by delivering hot blood from our core to the surface of the skin, from where we radiate this heat into the environment. The evaporation resulting from sweating also helps cool our skin. We get into trouble when the environment is too hot or humid for these mechanisms to cool us down.
Who is at risk for heat illness?
Heatstroke in healthy people is often associated with exercise because exercise raises body temperature. This is especially true if you are not very fit or are used to exercising in cooler weather. As addition, as you get used to exercise in the heat , your body learns to more effectively cooled.
Factors that increase your risk of heat exhaustion and heatstroke include:
- Exercising in high temperatures and high humidity
- Poor physical condition
- Be big (whether obese or very muscular)
- Dehydration
- Wearing or carrying equipment such as soccer pads or a backpack.
- Alcohol consumption
- Using certain medications or supplements, including beta-blockers and diuretics.
- Any disability or illness that makes it harder for you to get out of the heat or cool off.
Signs and symptoms of heat exhaustion
Heat exhaustion occurs when your body temperature rises, but not enough to energize your brain. If you or an overheated friend show any signs of confusion, for example, assume it is heatstroke and seek immediate medical attention.
According to the CDC, signs and symptoms of heat exhaustion may include:
- Dizziness
- Nausea and vomiting
- Headache
- Tiredness or weakness
- Heavy sweating
- Cold, pale and clammy skin
- Fast, weak pulse
If you start to feel these symptoms, immediately start to cool down: move to the shade or air conditioner, relax your clothes, have a cold drink, and watch for any signs that you are feeling worse or not getting better. If you have not recovered within an hour, seek medical attention.
Signs and symptoms of heatstroke
Heatstroke occurs when the body temperature is extremely high (over 104 when taken rectally) and can affect both the brain and the body.
Heatstroke is a serious condition, so seek immediate medical attention if you suspect it. If you are at an event with medical personnel (for example, if you are running a marathon or playing soccer), alert them. If not, call 911 or the emergency number in your area. Signs of heatstroke may include some of the above symptoms, such as headache, dizziness, and nausea, as well as:
- Confusion, irritability, or hallucinations
- Fainting or fainting
- Problems with walking
- Convulsions
- Redness of the skin with or without sweating
You can help the person cool down while you wait for help. Medical staff may decide that it is best to cool the person before being transported to the hospital, but this depends on whether the person needs other treatment. The ideal way to chill someone with heatstroke is to put them in a bath of cold ice water and stir constantly.
If this is not possible, you can use a cold shower or cold hose, or apply ice damp towels to the person’s body and change them every three minutes or whenever they are no longer icy.
This post was originally published on July 6, 2018 and was updated in June 2021 to reflect the current information and style.