Heat Exhaustion vs. Heat Stroke: How to Tell the Difference

Most heat stroke cases are preventable. Understanding why the body overheats, who faces the highest risk, and how to stay ahead of rising temperatures can keep a summer afternoon from turning into a hospital visit. At Conemaugh Health System in Johnstown, Pennsylvania, we want our neighbors to enjoy the season safely. Here is what to know before the next stretch of hot weather arrives.

Why the Body Overheats

Your body works constantly to keep its core temperature near 98.6 degrees. When temperatures climb, it responds by sweating and by sending more blood to the skin so heat can escape. Two things can overwhelm that system. High humidity keeps sweat from evaporating, which is how the body sheds most of its heat. And dehydration reduces how much you can sweat in the first place. When both happen at once, core temperature rises quickly.

What Separates Heat Exhaustion From Heat Stroke?

Heat exhaustion is the body straining to cool itself. It causes heavy sweating, weakness, nausea, and dizziness, and it usually improves with rest, fluids, and a cooler environment. Heat stroke is the failure of that cooling system. Core temperature reaches 104 degrees or higher, mental status changes, and the brain, heart, kidneys, and muscles can be damaged without rapid treatment. Heat exhaustion is a warning. Heat stroke is an emergency.

Who Is Most at Risk?

Anyone can develop heat illness, but some people are more vulnerable. Risk also rises with the heat index, which combines temperature and humidity to reflect how hot it actually feels. Pay closer attention on days when the heat index climbs above 90 degrees, especially for:

• Adults age 65 and older, whose bodies adjust to heat more slowly
• Infants and young children, who heat up faster than adults
• Outdoor workers, athletes, and anyone exercising in the heat
• People with heart disease, diabetes, obesity, or other chronic conditions
• People taking certain medications, including diuretics, blood pressure medicines, and some mental health medications
• Anyone without reliable access to air conditioning

How to Prevent Heat Illness

A few habits go a long way during hot weather:

• Drink water throughout the day, before you feel thirsty
• Plan outdoor work and exercise for early morning or evening
• Take regular breaks in shade or air conditioning
• Wear lightweight, light-colored, loose-fitting clothing
• Give your body one to two weeks to adjust when heat arrives or when starting a new outdoor routine
• Limit alcohol and caffeine, which speed up fluid loss
• Never leave children or pets in a parked car, even briefly
• Check on older neighbors and family members during heat waves
• Check the daily forecast and heat index before long stretches outdoors

How Heat Stroke Is Treated

Rapid cooling is the priority. Emergency teams may use cool water immersion, misting with fans, ice packs, and IV fluids to bring core temperature down quickly, then monitor the heart, kidneys, and other organs for damage. Some patients need a hospital stay. Recovery matters too: After any serious heat illness, the body stays more sensitive to heat for a week or more, so rest, hydration, and avoiding strenuous activity in the heat are important.

When to Talk With a Provider

If you or a family member has a chronic condition, takes daily medications, or has had heat illness before, a short conversation with your provider can help you plan for hot weather safely. Your care team can review your medication list, suggest hydration goals, and flag warning signs specific to your health.

Talk with a primary care provider at Conemaugh Health System in Johnstown, Pennsylvania about how your health conditions or medications may affect your risk in the heat. To learn more or schedule an appointment, visit Conemaugh Health System today.

This article is for general education and is not a substitute for professional medical advice.