Why Does Spending Time In The Sun Make You Tired?

The summer means spending time outside, going to the pool, cooking food on the grill, or, maybe, simply reading a book on the patio. However, being outside also means spending time in the sun, which can cause different effects on the body.

You may receive a sunburn, which is inflamed skin that hurts to touch and may even feel hot, caused by spending too long in direct sunlight without proper protection, according to MayoClinic. There are positive effects from the sun as well. When you are exposed to sunlight, your body converts cholesterol into vitamin D, a necessary compound for your health, explains Healthline.

Relaxing in the sun can have positive and negative consequences, or it can simply make you feel very tired. Have you been lounging in a hammock or reading on the beach when you suddenly feel the urge to take a nap? It's more common than you might think.

When you spend time in the sun, or high heat in general, your body tries to cool you down in a variety of ways. You may begin to sweat, a process started by the hypothalamus (the part of your body that helps to regulate temperature). It releases water from the middle layer of your skin when you become overly hot, eventually evaporating and cooling the body, explains Rush Medical Center. This explains why you sweat during workouts.

However, your body needs to use energy to cool you down. The blood vessels in your skin will widen in a process called vasodilation. That causes your skin to become flushed, explains UW Medicine. This is also why you may flush when you kiss someone you like or become embarrassed; your body is cooling you down through vasodilation. However, the blood doesn't just come out of nowhere. It's transported from other parts of your body to where it is needed, making you sleepy, according to MedicalNewsToday.