My 11 month old son has had heat rash for a couple of days, quite badly. He's been very grumpy today with what seemed like teething pain to the point that he didn't eat his lunch (unheard of for him!) I was giving him his bedtime bottle and I noticed he had a single small purple spot under his left armpit which doesn't fade when you run a glass over it. I've called 111 and they've booked us in at OOH at 12:20am. My gut instinct at first was to panic, but as time has passed I'm not sure if I should be worried or not. Just been to check on him and he's sound asleep, we took his temperature which was 35.7 so quite low. Wondering what others would do in this situation.