Winter season is when days are slow, cold, and wet. Apparently, personal hygiene used to go out the window when the cooler weather blew in. During winter, of the past did away with washing their clothes, mainly because it was too cold to take them off.
It’s a fair point when you think about it. After all, during winter, it’s very cold and you don’t sweat a lot, so you could be forgiven for feeling like you don’t need a fresh change of clothes. Regardless of their reasons, I do hope they still thought to change their underwear once in a while.