Izuzu rodeo 1999 tranmision

First what is "wen the car gets hot?" Any vehicle getting hot essentially is put in survival mode. The engine light - is it working correctly? When the engine gets HOT the heat transference makes the transmission =HOT= fluid breakdown occurs faster than motor oil because the engine is exposed to higher temperatures and the cooling system is designed forthose extremes. The transmission is not as well cooled and therefore not designed for those extremes. WHY NOT??? A safety regulation on how hot your engine can get due the poisonous fumes produced and the industry sacrificed the transmission if the operator was chronic in exceeding the boundaries. Knowingly or not is depending on the auto exposure/education the person had. The trans. fluid breaks down very quickly by comparison so a fluid change exposed to the same extemes would not survive long.