Does sunlight itself make you tired? Why?

I love the sun, and heat. But taking my shirt off and getting lots of full-on sun even for just five or ten minutes makes me want to go inside and take a nap. That’s what I just did.

I almost never can nap during the day. Wish I could more often, but it just ain’t happening. Then a little time shirtless in full, hot sun and I’m overcome with a tired lethargy; gotta sleep!


If it’s hot at night, I can’t sleep, so it’s not just the heat. It seems to be exposure to the sun, then shade that triggers a sleep reflex, hot or not.

Do you also enjoy feasting on the blood of the living? Because if so I think I can diagnose what your problem is.

More seriously, usually when I hear people complain about the sun making them tired, they’re talking about a few hours of exposure wearing them out, like how people coming back from the beach are always wiped out even if all they did there was sit on a towel and read. I suppose due to some mixture of dehydration and sunburn. But I’ve never heard of anyone being exhausted by just a few minutes of exposure.

I have no factual information, but if you open a poll thread in IMHO I’ll be happy to tell you that sunshine makes me sleepy, too.

I won’t start a new thread but if it appears a factual answer isn’t forthcoming, I’m more than happy to have a mod move this to IMHO and treat it as a poll.

Here’s another piece of data. Sun in a car, even in the winter, makes my entire family drowsy. That is, when you’re sitting in a car and the sun is beating down. Probably especially in the winter - in the summer it’s too hot.

Makes me sleepy as well. It also makes me sneeze.

Hmmm…many creatures rest when it is hot out.

My educated guess is that this is a built in reaction by your body to conserve energy, focus on cooling and prevent dehydration. Survival-wise, it’s better to have a natural tendency to stay hydrated and rested than it is to have a natural tendency to want to run around, overheat, dehydrate in the sun and increase the chance of death.

Many years ago, I lived in an apartment right on the beach, in Long Beach, NY (on the southern shore of Long Island). I was working the graveyard shift in Manhattan, and was having a helluva time trying to sleep during the day in summer, what with the beach crowd’s noise and kids playing basketball next door. I discovered that if I went out to the beach, with lots of sunscreen, I could get at least a few hours of sleep, then come inside and go immediately to bed.

Behold, the photic sneeze reflex! You are not alone.

Welcome, Stathol. We like that kind of early post around here. Brief, factual, includes a cite. Keep up the good work! :slight_smile: