Heat Exhaustion vs Heat Stroke: What’s the Difference?

Warmer weather can signal beach trips, barbecues, and other fun outdoor activities. But when temperatures soar, your risk of heat-related illness (hyperthermia) rises, too.

Two well-known types of heat illnesses are heat exhaustion and heat stroke. Both of these conditions happen when you’re exposed to extreme heat or humid weather for too long. This causes your body’s internal temperature to rise and can also cause dehydration.

However, heat exhaustion and heat stroke vary in terms of severity, symptoms and treatment. Read on to learn more about the differences between these conditions, along with treatment and prevention measures.

What is the difference between heat exhaustion and heat stroke?

Both heat exhaustion and heat stroke are forms of heat-related illness. However, heat exhaustion is considered more mild and can generally be treated by hydrating, resting and cooling down. Heat stroke is far more severe and is a life-threatening medical emergency.

Heat exhaustion happens when the body becomes dehydrated. This is generally a result of fluid loss from sweating and can be caused by high temperatures or strenuous exercise. Some common signs of heat exhaustion include heavy sweating, weakness, dizziness, headaches, nausea, muscle cramps and a rapid but weak pulse. If not addressed, it can quickly develop into heat stroke.

Heat stroke happens when extreme heat or humidity causes the body to lose control of its own temperature regulation system. As a result, your core body temperature rises. Heat stroke can damage your brain and other vital organs, and can be deadly if not treated right away. Symptoms of heat stroke include a body temperature about 104°F (40°C), dry skin (sweating may be absent), confusion, seizures, loss of consciousness and a rapid, strong pulse. Heat stroke requires immediate medical attention to prevent serious complications or death.

How to tell the difference between heat exhaustion and heat stroke

Knowing the difference between symptoms of heat exhaustion and heat stroke is critical. Here’s how to spot the warning signs of both conditions:

Treating heat exhaustion

If you or a loved one is showing signs of heat exhaustion, these measures can help:

• Move to an air-conditioned, cool place
• Drink sips of cool water, an electrolyte sports drink, or another fluid to ensure hydration
• Rest and avoid strenuous activities
• Place a cold compress over your forehead and/or neck to cool down

If the affected person isn’t showing signs of improvement after an hour or so, call your primary care provider for advice.

Treating heat stroke

If you or someone you know is exhibiting signs of heat stroke, you should call 911 immediately. In the meantime, do your best to cool down the affected person. Common first-aid measures for heat stroke include:

• Placing the person in a cool shower or bath to help bring down their temperature
• Putting ice packs on the person’s neck and/or armpits
• Removing unnecessary clothing and covering the person with cool, wet towels or blankets
• If the person is awake, offer them sips of water or another non-alcoholic, non-caffeinated beverage to help them rehydrate

Preventing heat-related illnesses

According to the Centers for Disease Control and Prevention (CDC), there were nearly 120,000 heat-related emergency room visits in 2023. However, there are many strategies that can help prevent heat stroke, heat exhaustion and other heat-related illnesses. These include:

• Using an air conditioner during hot weather
• Limiting outdoor sports and other physical activities on hot days
• Drinking plenty of water, and up your fluid and electrolyte intake if you’ve been working out or sweating
• Avoid alcoholic beverages or caffeinated beverages in hot environments, as these can dehydrate you
• Pacing yourself if you’re not used to exercising or spending time in hot environments
• Wearing light-colored, loose-fitting clothes that keep your body cool
• Being aware of any medical conditions or medication side effects that can cause fluid loss, decreased sweating or decreased heart rate
• Making sure that children or impaired adults are not left alone in a car or another enclosed space
• Use the National Weather Service heat index to see how different temperatures impact your risk of heat-related illness

Increased risk factors for heat-related illnesses

Some people are at higher risk for heat-related illnesses than others. Groups with increased risk factors include:

• Adults 60 years and older
• Athletes
• Infants and children
• Outdoor workers
• People with chronic conditions, such as high blood pressure, diabetes, obesity and heart disease
• Pregnant women

How Sesame can help

If you are at increased risk for heat-related illness due to factors such as obesity, diabetes or another condition, Sesame can help.

During an online doctor visit, a healthcare provider can offer effective prevention strategies and advice based on your medical history and current medications. This personalized care can help you stay safe and enjoy warm weather without compromising your health.