You need to keep him warm, and get some fluids into him ASAP !!! Wrap him in fleece
Mix Orange gaterade and water a 50 50 mix you may need an eye dropper or feeding syringe hell even a drinking straw with a little at the bottom if you have to to get him to take some liquid. If you have pedialite you can use that instead of gaterade
You are going to have to keep giving him liquids and keep him warm next to your skin if you have to.
Do NOT just leave him in the cage you will need to try to keep him alive through the night, What do you feed him? whens the last time he ate? where are you located ?
messaging on here takes forever I will be up for a little bit if you have facebook message me on there and I'll try to get you some help
https://www.facebook.com/carla.sloan.1
Your objective right now is to try to keep him alive until you can get him to a vet right now he probably has a 20% chance of survival
YOU NEED TO ACT NOW