I co sleep with my almost 6 month old and she's been in just a nappy the past couple of nights it's been really hot, if she wakes up I'll check he chest and put a vest on if she feels cold x
just turn the fan on or the ac.
@Eri houses in the UK generally don’t have AC and its advised against pointing a fan towards a baby!
Maybe just leave baby in a nappy! Sweat is just a sign that baby is too hot so might be better in less clothing! X