I already had a 10.5 tog duvet and wanted one for summer. When I saw the claims that is duvet was supposed to be good all year round and would keep you cool in summer as well as itâs other features like sustainability, I thought great! However, Iâve hardly been able to use it in summer so far for overheating. I feel like it was a bit of a waste of money for my needs. Itâs a nice duvet but now I have 2 10.5 tog duvets neither of which works in summer.