When the heat hits, you can see it on the outside of your body with the buckets of sweat you’re pouring out, but it’s affecting you on the inside, too, doctors say.
As the temperatures soar outdoors, the temperature in your brain goes up slightly, according to Dr. Michael Bergeron, the director of the National Institute for Athletic Health & Performance in Sioux Falls, South Dakota. This explains why people sometimes get confused when they’ve spent too much time in the heat.
When it’s hot outside, the body sends extra blood to the vital organs to keep them functioning, and to the skin, to help it cool off. This means less blood for your belly, Bergeron says.
“Digestion is less of a priority, so blood vessels to our gastrointestinal system restrict,” he says. “This is why you might not feel like eating or drinking when you’re out in the heat, or why you feel sick if you do eat.”
The solution: Eat foods that are easy to digest, like simply carbohydrates, and avoid foods high in protein or fat, which are harder to digest.
And of course, drink, drink, drink. Water or a sports drink are best, and stay away from alcohol or caffeine, which can dehydrate you.
In severe cases the heat can make you seriously ill.
Heat illnesses can start with cramps, says University of Alabama Birmingham Chair of Emergency Medicine Dr. Janyce Sanford. “As it progresses, the next step is heat exhaustion. They may develop a severe headache, nausea, vomiting, and a feeling of severe weakness.”