Sugar Glider Central

I have 2 eight weeks old boys. I have had them for about a week. Bonding is going very well. This morning I went to check on the boys and Timothy was laying on the top shelf, just out in the open (about a foot above his normal sleeping area), when I got closer I noticed he was sleeping there. I have a pouch near the top of the cage and an old t-shirt of mine in the bottom corner. I have a heat rock under the t-shirt. (I know some people don't approve of heat rocks, but my house can be drafty and I will take no chances with them getting cold.) They tend to prefer to sleep in the t-shirt together. If the boys had a fight or if Timothy had gotten too warm, why didn't he go to the pouch? Is it possible he forgot how to get down to the "nest" after some night time play?
When I picked him up he was cool to the touch, so I rubbed him and woke him up and let him climb around a bit and then put him in the warm t-shirt. He seems fine now. Is that normal or should I be worried?

Not normal.  keep a very close eye on him........................may even take to vet for well visit just in case. Gliders can be tricky with health. They are nearly dead many times before they show signs of illness!   

Cora,
What type of heating pad? I have a 9 week old (first time glider owner) and I've tried putting it under his tree trunk hiding spot in the tray so the heat will rise but it doesn't reach the trunk. The only way you can feel the heat is if its directly in the cage under the tree trunk. I don't feel safe leaving anything electric on in the cage and I only have it on when I can monitor it. The breeder close by says to use a sock to cover the cord near the cage so they can't chew on it. Any suggestions? Thank you!
April