Eli5: Why does being exposed to direct sunlight for multiple hours cause a feeling of strong exhaustion?

Question

Like when for example lying at the beach all day doing nothing, sometimes in the evening it feels like one had done hard physical labor?

In: Biology

Answer 1

A sunburn is exhausting because you’ve been cooked by the radioactive sky ball and your body needs quite a few resources to return to baseline. Maybe that applies to a lesser extent with a lot of exposure but no burn.