Immediate First Aid for Wild Animals

Wild life should be kept in the wild where they belong but if you find an injured animal this is what is recommend to do:

1. Keep the animal in a dark place, put into a box or cover with blanket to keep them calm
2. Keep animal warm to help reduce shock, by using a heating pad or hot water bottle, but put a thick towel between them and the heating pad, or hot water bottle so it doesn't get too hot or burn them.
3. Third this animal is probably dehydrated, baby pedialyte would help replenish the electrolytes and hydrate the animal, try to leave a dish of water out for them, birds have a different digestive tube and must be handled by someone that knows how to feed them, just leave water out for them they should drink it do not try to shove water into their throats with a dropper because the water might get into their lungs. Do not feed the animal as the dehydration may cause loss of energy to digest food and this could kill the animal, the food will not digest because the body doesn't have enough energy to digest the food properly due to lack of energy in the body.
4. Call your nearest Animal Rescue Team within 24 hours, they know how to treat the animal for any injuries that are obvious and any hidden injuries which could be life threatening.

http://www.squirrel-rescue.com/squirrel-diet.htm