I had a friend who would wake up because her feet were cold. She would get up and put socks on, then go into her child’s room and put socks on him, figuring that if she was cold, he was cold. I did my own version of this the other night.
I woke up at 4am because I had to empty my bladder and because I was thirsty. While I didn’t make Molly go outside in the very cold weather, I did make her wake up from a deep, deep sleep to drink some water. If I was thirsty, she must have been, too. She didn’t argue, but she was very confused. She went right to sleep again after the unplanned outing.