Now that summer is fully upon us, it’s important to be aware of—and protect yourself from—the risk of heat stroke.

Heat stroke is a potentially fatal condition caused by overheating. Signs and symptoms include nausea, vomiting, flushed red skin or a heat rash, rapid pulse, muscle cramps, extreme or sudden fatigue or weakness, headache, dizziness, difficulty breathing, confusion, agitation, hallucinations, or fainting. If heat stroke is suspected, it’s important to cool the person immediately by getting them to shade or an air-conditioned room, removing excess clothing, immersing them in, or spraying them with, cold water, and seeking medical attention.

Heat stroke is caused by the body’s internal temperature rising to 104⁰ or higher—causing the brain and nervous system to begin shutting down. (Your cell phone will do the same if you leave it in the hot sun!) Heat stroke usually occurs when a person is exerting herself in hot, humid conditions, or is dehydrated, meaning the body cannot produce enough sweat to cool itself sufficiently. (Yet another reason to eat your water!)

Although athletes and people who work outdoors—such as carpenters, roofers, street pavers, firefighters, etc.—are whom we usually think of as being at-risk for heat stroke, others who are susceptible include the elderly (who may be taking medications that make them more vulnerable to dehydration), infants, pregnant or breastfeeding women, and pets.

Sunscreen is no protection against heat stroke because, while sunscreen protects your skin from burning, it can’t protect your internal temperature from rising to unsafe levels. The only way to do that is to:

Stay hydrated. Drink plenty of fluids if you will be out in the sun for extended periods.

Take frequent rest breaks out of the sun.

Limit your intake of coffee and alcohol, both of which are dehydrating.

Carry a water bottle for head-dousing, or keep a wet cloth tied around your neck or over your head.

Wear light-colored, evaporative clothing that allows your body’s natural sweat-and-air-cooling system to work.

Eat smaller, more frequent meals, such as salads and sandwiches, so that you don’t add the heat of digestion to a heat-stressed body.

Eat watermelon! (As I’ve noted previously, watermelon is 92% water—the most water-rich fruit—a great-tasting way to stay hydrated. Watermelon also contains vitamin C and lots of powerful antioxidants, including one—lycopene—which actually protects your skin against sunburn.)

Plan your outdoor activities to take place in the cooler mornings or evenings, avoiding the mid-day sun.

And finally:

Wear sunscreen! Just because sunscreen can’t protect you from heat stroke, doesn’t mean it isn’t essential to your health. After all, skincare is healthcare. When you damage your skin, you’re damaging your body’s largest organ. Protecting your skin is the first step in protecting your body!