My Son is 2+ year old. We often see that his temperature (measured in armpit) shows 99+ when he is playing.Then automatically come down.I see this behaviour since past 1 year.Temperature fluctuates between 99.3 (while playing) to 96.5 while sleeping.Please advise is it ok to have 99+ temperature while playing? Also Is there a way I will figure out if temperature rise i.e 99+ is due to environment heat/playing and not fever? Please advise