Me, most nights: My feet feel warm enough, so I don't need to turn on my foot warmer (heating pad).
I turn it on anyway.
Also me most nights: I HAD NO IDEA MY FEET WERE SO COLD! I LOVE YOU, FOOT WARMER!
And that's why I always turn on my foot warmer. There will always be many cool spots in bed, and I don't always know I need that hot spot until I use it.
Cold feet prevent me from falling asleep, so this helps with one aspect of my insomnia.