4 week old feeding less - hot weather?

[citymonkey]

my 4 week old has been feeding a lot less today - 10 mins total vs usually 15-20 mins per feed (and a bit yesterday) and has been v sleepy today - could this be because of the hot weather? We are in London. I am frantic with worry :-(

Have they still had wet and dirty nappies as usual? My LO (5 weeks) has been having shorter feeds too but a bit more often - I figured he is getting thirsty and doesn't really want the richer milk just the thirst quenchy bit at the beginning. Must admit I'm hoping the weather cools down now because keeping a newborn comfortable in the heat hasn't been easy :/

Yes still wet and dirty nappies, and think also feeding bit more frequently. Nightmare as room is 25 degrees though have managed to get it down to 22 now...