What is wrong with my pet rabbit, and how can I make him more comfortable?

this happened to my rabbit once, keep it inside maybe put some towels down and if you have a small rabbit run place it in there to keep it warm, place a bowl of water down rather than the bottle, try make it drink, then try get it to eat, mine did this and then soon became better, but it did die about a month later so i would take it to a vet asap but this should make it feel better