But if it’s suspended off the ground on a metal bed frame, it will eventually warm up nicely, and you’ll throw off your duvet and sleep with one sheet and blanket in the winter. If my bedroom were colder, I’d buy an electric blanket to turn on 30 minutes before bed, and turn off before crawling in.
I have a “sleep number” bed. A quadriplegic in my building had one as well, but it made him sweat so much he had to get rid of it. The air mattresses inside were too insulating, and he couldn’t regulate his body temp enough for it. They don’t mention this aspect of the internal air mattresses to customers.
In the summer, a sheet is sometimes too much.