My DS is in a cot bed and at the moment he has a flat sheet and a thin quilt type blanket. It gets cold in his room overnight and he wakes up early in a morning because he is cold. I was wondering what type of duvet he can have on his bed? We have a few single bed duvets already but I'm not sure what tog he should have. Can he have a normal sized single bed duvet or are cot bed duvets more suitable? I don't want him over heating but he needs to be snug! TIA