My LB has this. We even ended up at the cardiologist! They explained that while it might feel warm to us babies regulate temperature differently and can still be warm in the body but cold in the extremities (hands, lips, ears) Go to GP and have her heart listened to for your own piece of mind and it’s always good to check with these little humans but apparently it’s super normal! I freaked out once when his bottom lip was like proper blue I thought he couldn’t breathe or something but next thing it was pink again and he was busy playing
We had a little boy in my pre-school that would have this all the time, his mum was a nurse and was never concerned, just one of those things I guess!
My daughter had exactly the same, first few times assumed she was cold then took her to the GP. They passed it off as her having a respiratory virus and said it’s normal when they have a bad virus. It hasn’t happened since but if it does I’ll be straight back to the GP! Probably nothing to worry about but could be a sign of something more serious so worth speaking to a medical professional, especially if not while they have a cold/out of breath ect x