Well, Mic has just discovered exactly what happens when you go to sleep with wet hair and let's just say you might think twice about doing it again.
"Sleeping with wet hair doesn't do any particular damage to the hair shafts themselves, but it does make it more likely your hair could be flat, frizzy or generally dull-looking when you wake up," dermatologist Jessica J. Krant said.
So you're ok with a ~slight~ bad hair day? There's something else you need to know...
"Each hair shaft is almost 'like roof shingles' that stand up in one direction. However, when your hair is blowdried with gentle smoothing they lie flat (as long as it doesn't overheat them, of course)," Jessica added. "When you sleep with wet hair, your cuticles end up lying in different angles, thereby reducing the reflective shine and seal of any given shaft and making it seem dirtier."
Ok that's a bit much. Nobody wants flat, frizzy or dull hair with no shine that looks dirty! No more wet hair in bed for us!