Heat Stroke vs. Heat Exhaustion: Know the Difference to Stay Safe

Every summer, I treat people suffering from heat-related illness. Some cases are mild, but others are serious and even life-threatening. As an emergency physician, I want to help you understand the warning signs of heat exhaustion and heat stroke, how to prevent them, and what to do if they happen. 

What Causes Heat Exhaustion and Heat Stroke? 

When your body gets too hot and can’t cool down, you’re at risk of heat-related illness. This can happen during outdoor activities, work, or even just sitting in a hot house without air conditioning. You may sweat a lot, lose fluids and salt, and start feeling sick. 

Heat exhaustion is the early stage. It’s serious but treatable. If not managed quickly, it can lead to heat stroke, a life-threatening emergency. At this point, the body can’t control its temperature, and organs can start to fail. 

Symptoms I Look for in Patients with Heat Exhaustion 

According to the Mayo Clinic, common symptoms of heat exhaustion include: 

• Cool, moist skin with goose bumps when in the heat 
• Heavy sweating 
• Faintness 
• Dizziness 
• Fatigue 
• Weak, rapid pulse 
• Low blood pressure upon standing 
• Muscle cramps 
• Nausea 
• Headache 

When someone comes to Immediate Care with these signs, we move fast to cool them down and replace fluids. The key is to act before it gets worse. 

What Makes Heat Stroke So Dangerous? 

Heat stroke is much more serious. I always tell patients that if someone shows these symptoms, they need emergency care right away: 

• Body temperature over 104°F 
• Hot, red, or dry skin 
• Strong, fast pulse 
• Confusion or slurred speech 
• Seizures 
• Loss of consciousness 

Heat stroke can cause lasting damage to the brain, heart, and kidneys, or even death, if not treated right away. 

How to Prevent Heat-Related Illness 

The best treatment is prevention. Here’s what I tell my patients: 

• Hydrate. Drink plenty of water before, during, and after being in the heat. 
• Dress smart. Choose light, loose-fitting, or breathable clothes. 
• Avoid peak heat. Try to stay indoors or in the shade between 10 a.m. and 4 p.m. 
• Take breaks. Don’t overdo it, especially during outdoor work or exercise. 
• Watch others. Keep an eye on older adults, kids, and anyone with a health condition. They’re at greater risk. 
   

What to Do if You or Someone Gets Overheated 

If there are symptoms of heat exhaustion: 

• Move to a cooler place. 
• Loosen clothing. 
• Apply cool cloths or take a cool shower. 
• Drink water or a sports drink. 
• Rest and watch for signs of worsening symptoms. 

If there are symptoms of heat stroke: 

• Call 911 immediately. 
• Move the person to shade or air conditioning. 
• Remove extra clothing. 
• Use ice packs, fans, or wet cloths to cool the body. 
• Don’t give fluids if they’re confused or unconscious, as they may choke 
   

A Message from Immediate Care 

If you’re ever unsure whether it’s heat exhaustion or something more serious, please don’t wait. We’re here to help. At any of our five Immediate Care locations, we treat heat-related illnesses and more, seven days a week. 

You can also skip the trip with an Immediate Care Virtual Visit! Connecting you with trusted health care from experienced local providers when and where you need it. 

Dr. Dilip Yarabothu is a board-certified emergency physician with over a decade of experience in the medical field. After serving full-time in the emergency department at Southern NH Medical Center, he is now providing care to patients of our Immediate Care locations in the southern NH area. He recognizes the importance of providing healthcare that fits into patients' busy lives and has joined the growing telemedicine team to better serve our community.