Hi, thanks for the information. I have some new information this morning. The first time I noticed Sid breathing like this was after the cat swatted him. I thought he was mad and hissing at me. Last night when I noticed it again I just assumed it had never stopped but I could be wrong. My husband is the high school varsity tennis coach and he had a party for his boys last night and of course they all wanted to handle Sid. This is when I noticed it happening again. However, I just spent an hour with him slithering all over me and the floor and he didn't wheeze once. Could it be a hissing from a scared reaction? My husband thinks I should watch him to see if and when it happens again rather than trying to get him to a vet since he has no other symptoms. I don't want to be irresponsible with his care but I do see my husband's point. It would not be an enjoyable trip for Sid either and if he is just scared and making a hissing noise it would not be in his best interest to drag him to vet with all the other animals he would come into contact with. His cage stays pretty much between 48% and 52% humidity and the cool end is 75-77 degrees F and the hot end is between 83-85 degrees F. His new humidifier should be here tomorrow. I usually try and keep it around 55-57%. I really do appreciate the help! elysheva