My baby is 4 months old and has always had problems with sleeping.. This started improving and she was only waking up 1-2 times a night. For a week now she's been waking up about 4 times a night and during the day after about half an hour of being awake she's tired again, rubbing her eyes and being grouchy. She's also drinking less aswell. I've tried moving her up a teat size but the flow is too fast for her as she coughs. Do you think this is all just sleep regression or could it be down to the heat?