How to Stay Cool and Prevent Heat Illness All Summer Long

When the temperature hits 90 and stays there for days, it’s important to take precautions to stay cool. These tips can help you and your loved ones stay safe in a heat wave.

A male in his 30s drinks from a water bottle on a sunny day, with trees in the background

Updated July 25, 2025

By Monika Smith, DO, Emergency Medicine Physician, Chair, Department of Emergency Medicine—Virtua Our Lady of Lourdes Hospital

Summer brings sunshine, pool days, and cookouts, but when temperatures climb into the 90s (and stay there), heat-related illness becomes a serious concern.

When the temperatures hit record highs and stay there, it's important to take precautions to keep cool—and to make sure your loved ones do, too. According to the Centers for Disease Control (CDC), heat waves claim more lives than all other weather events, with an average of 618 heat-related deaths per year in the U.S.

These tips can help you and your loved ones stay safe during a heatwave:

Hydrate before you feel thirsty. Try to drink at least a half-ounce of water for each pound you weigh. If you weigh 150 pounds, you should aim to drink a minimum of 75 ounces of fluids per day.
Be mindful of your time spent outdoors. Try to limit your outdoor activities to early or late in the day. Set a timer on your phone for about 30 minutes and then come in to cool off.
Wear sunscreen. To prevent sunburn and block the sun's most harmful rays, the American Academy of Dermatology recommends using at least SPF 30. Reapply more often if you're sweating or swimming.
Know what medications affect your body's ability to regulate temperature. Some commonly used medications for managing AD/HD, allergies, blood pressure, depression, and thyroid disease make it more difficult for your body to regulate your temperature. Check the detailed side effects on the informational pamphlet that comes with your medication or discuss it with your primary care doctor or pharmacist.
Monitor your children when they're outside. Outdoor playtime is essential for children's health and physical development, but high heat can put them at risk for heat illness. Check on your kids often to make sure they're not overheating, and reapply their sunscreen often. Make sure they're drinking water or sports drinks (low or no sugar) to stay hydrated.
Check in with the older adults in your life. Older adults don't adjust well to sudden temperature changes, or they may have chronic medical conditions or take medications that affect their body's ability to regulate their temperature. High heat also can create stifling indoor temperatures that even fans can't relieve. The Low-Income Home Energy Assistance Program (LIHEAP) may be able to provide assistance with paying for home cooling. It also helps to spend time in a mall or library during the hottest part of the day.
Look out for your athletes. If you have family members practicing for or playing sports, it's best to limit their outdoor activities to early or late in the day. They also should drink more water than usual to stay hydrated and avoid muscle cramps during moderate to vigorous activities.

Know the warning signs of heat illnesses

There's a range of heat-related illnesses with varying symptoms. It's important to be able to recognize the signs to prevent severe or life-threatening heat illness.

Here's what you need to know:

Heat rash

More common in kids.
Signs include small, red pimple-like blisters on the neck, chest, groin, and elbow creases.
What to do: Get into a cool place and keep the rash dry, using powder if necessary to soothe the rash.

Sunburn

Signs include painful, red, warm skin with or without blisters.
What to do: Stay out of the sun until sunburn heals and don't pop blisters. Apply moisturizing lotion to sunburned areas and apply cool cloths or take cool baths for relief.

Heat cramps

Usually occur during vigorous exercise.
Signs include heavy sweating and muscle cramping, pain or spasms, especially in the leg muscles (quads/hamstrings/calves) and arms.
What to do: Stop your activity and go to a cool or shady area. Drink 8 ounces of water or sports drinks with electrolytes every 30 minutes until you can urinate. Don't resume activities until your muscles cramps stop. If muscle cramps last more than an hour, get medical help right away.

Heat exhaustion

Signs include heavy sweating, rapid heart rate, nausea or vomiting, dizziness or a feeling as if you're about to pass out, fatigue or weakness, cold or clammy skin.
What to do: Stop your activity and move to a cool place. Remove as much clothing as you can and place cool cloths on the body to lower your temperature. Take sips of water or sports drinks until you start to cool down, and then drink 8 ounces of every 30 minutes until you can urinate. If your symptoms get worse or don't improve within an hour, seek medical help right away.

Heat stroke

Signs include body temperature higher than 103 degrees, hot, red, dry skin, rapid heart rate, headache, nausea, confusion, dizziness, fainting, or loss of consciousness.
What to do: Call 911. A heat stroke is a MEDICAL EMERGENCY that requires IMMEDIATE medical care. Move to a cool area. Remove as much clothing as you can and place cool cloths on the body. DO NOT drink anything.