Anonymous wrote:For fresh air. OP, how come you couldn't think of that? It's so obvious. I cannot sleep with all the windows totally closed, feel claustrophobic and feel like I will choke without fresh air, even when its cold outside. I really do not enjoy sleeping hotel rooms where I am not able to open the windows at least a tiny bit. I am European if that counts.
I am guessing OP is like me and grew up with parents yelling at them to immediately close the door in the winter because we are not paying to heat the outdoors.