Even if you wear shoes throughout the day with your socks, it’s always a good idea to swap out the dirty pair for fresh ones before heading to bed, according to Carlie Gasia, a certified wellness coach at Sleep Advisor (via House Beautiful). “Dirty socks can accumulate bacteria that have the potential to spread in your bed, possibly posing health risks,” explained Gasia. “Also, if your feet tend to sweat, your socks may retain bacteria that has transferred from your shoes.”

It’s not just the gross smell of sweaty or moist feet rubbing against cloth that you have to worry about. You’re risking getting fungal or bacterial conditions, itchy feet, athlete’s foot, and cellulitis, too, shares doctor of podiatric medicine Dr. Wenjay Sung (per The Healthy). 

But does this mean you shouldn’t be sleeping in socks? Not necessarily, say the experts. In fact, there are plenty of health benefits to covering your feet with this warm piece of clothing at night. One has to do with distal vasodilation, the process of body temperature dropping in preparation for sleep, per behavioral sleep disorders specialist Dr. Michelle Drerup (via Cleveland Clinic). “By making your feet warmer, you’re opening up blood vessels to help cool down the rest of the body.”