Very confused now, so looking for some advise. DS is 4mo, formula fed, feeding 5 times a day, 180ml bottles, so this seems fine for his weight and age. But we are now away on holidays and having some really hot weather here. The only difference is that he is now finishing all his bottles (which he never used to do at home) and seems quite happy most of the time. I've had a few people mentioning to me today that I should be giving him more formula or just water now when it's so hot. Should I really be doing that? I am not convinced about water or any additional drinks... and he doesn't seem hungry so why should I be giving him more formula?