Of all the things you shouldn't wear to bed, underwear is probably the weirdest one.
But research suggests that wearing underwear to bed can be hazardous to your health, increasing the risk of infection, and in the case of men, affect fertility.
Gynecologist Alyssa Dweck, M.D. told Shape:
I often tell my patients to sleep without underwear.
If [the groin] is constantly covered – especially by a fabric that’s not moisture-wicking or absorbent – moisture collects.
That’s the perfect breeding ground for bacteria or yeast.
It's not just women who benefit from sleeping commando though.
Sleeping in tight underwear is bad for men also, and it may reduce their sperm count.
A study in the 1990s got the study sample to alternate between wearing loose and tight underwear to bed for a year.
During the tight underwear periods, men had sperm counts of only half as much as during the loose underwear periods.
The loss of sperm is, however, reversible.
Just in case you needed a reason to sleep naked...