That's BS. Everyone just "happens" to sleep nude all the time.. I don't believe it for a second. I'm *ALWAYS* cold. and I love PJs... so, long cotton pj pants occasionally a shirt with them... sometimes I go like Tiger in a small-ish t-shirt and cute panties.. or just the cute panties... almost always with socks ( my toes are frozen non-stop) in the winter, long sleeve shirts/hoodies and pant and 2 socks per foot.
When it's hot.... of course, I'm naked just like everyone else.
j/k
btw... I live in FL... and I'm always cold.... God help me if I ever move further North.