Depends.... how long does it stay at 80%? If its just spiking but comes back down over the course of an hour its not a big deal. I keep a portable heater in my snake room cause its cooler downstairs in it, but because it eats up the humidity. I mist the substrate in my tubs every evening since my humidity will drop everyday from 60% down to 40%. Price to pay but for now its what I gotta do.