My two year olds temperature is 104...when does high temp become dangerous?

There: Depends on how long and whether you can keep him hydrated throughout the illness. Above 102-103 he needs seen by his doctor.

Condition not temp: Kids febrile response to illness is more a gauge of how well their body rejects the germs than how serious the illness.I've had kids with 105 giggling & running down the hallway while some with 100.4 couldn't move without pain.Any kid with sustained t >102 for >12hrs deserves a dr visit.I am more concerned about taking fluids, wet diapers & play.A 7yo with 107 last yr with flu did quite well.