Scientists have long advocated the theory that sleeping without underwear is good for your health. But, now men are being forced to sleep this way also for an essential reason related to their ability to give birth to offspring.
The human body is created to play with temperature during sleep, so sleeping without clothes helps it to accurately determine body temperature. Moreover, scientists point out that sleeping without clothes helps the body also determine the schedule when it is ready to fall asleep or get up from it.
Experts go on to say that sleeping in underwear affects the quality of sperm in men as it creates unnecessary heat in the genital area. In order to increase the chances of fertility, it is best to sleep without clothes! In addition, the quality of sleep will improve as the chances of waking up at night decrease and the amount of calories burned by the body increases.
Source: Bustle