Thank You for reply-I cant say what the humidity level was during last cold season since I just got the Hygrometer.I now keep an eye on it and level indicated.I am guessing that a "danger zone" would be below 70%.But I am trying to maintain a level of about 80% due to the snake not eating for entire winter last year.I was also wondering if they might shutdown naturally during a cold season.But I think their locale is on the warm side.Anyway I had to throw out practically a whole supply of rodents.Anyone who experiences this knows its the darker side of the Reptile world.