Good - that is a good sign, will he eat? Try him with any treats he likes - meal worms, steak, toast and butter - my kiddos go nuts for toast - I have a very hard time eating toast around them.He’s drinking!Electrolytes in the water. But he has a hard time opening his eyes.
Don’t worry about him keeping his eyes open, he could just be completely exhausted. Keep him warm and quiet and get some sugar water into him - actually some toast with honey would be good, honey is what athletes use on marathons it’s a perfect sugar easy to digest.