I've always slept nude as long as I can remember, I had to sleep with a rubber sheet under my regular sheets when there was still the threat of bedwetting
That's just what we choose to do. More so that my wife isn't comfortable being nude in front of the kids, and that our daughter is still at the age where she comes to our room a lot of nights due to being scared of the dark and bad dreams. Lately things have eased up a little there, so we will sleep nude on nights when we've had sex. We just keep the door shut & locked and clothes at the ready if one of the kids come knocking.
Funny that I wrote about this not long ago. In the last week or two we seemed to have crossed a threshold in that neither of our kids is prone to waking up during the night anymore. As a result, my wife has enthusiastically returned to wanting to sleep nude every night, not just after sex. Last night before bed, I took a shower and put a pair of pajama shorts on, out of habit in case either of the kids were to wake up. She went in the shower after me, then came out nude after she was done. She took one look at me and said "what are you doing with clothes on?". I had to laugh because it was just a habitual thing after not regularly sleeping nude for a while - so I said "I'll be happy to take these off", and did just that. I have to admit that I was kind of turned on hearing her say that. Sleeping is so much better now that we're nude every night. Still waiting for the spontaneous middle of the night sex like we used to do.
I can't remember when I started sleeping nude but certainly not during winter time in the beginning. I do know that is was before my teens. When I was 15 I crashed with my bicycle on a hot mid august day and ended up in hospital, the damage was a severe concussion and a broken colar bone. The hospital was ran by nuns and most of the nurses also nuns. I was not allowed to stay in bed naked so mom went to buy me a new pair deep purple pajamas. In the morning after a very hot and sweaty night the nurse insisted that I strip naked to get washed. She was in for a big job because my body was covered with large purple stains.
I was born in the tropics, so hot and humid the only way to sleep. No other way. With just a mosquito net over us, at night and a fan with ice qubes behind the fan to cool the air a little. No AC in those days for us .