What is the right room temperature for a 4 month old rabbit?

Cottontail rabbits are wild animals. Wild animals should pretty much be left alone. Pet rabbits have been domesticated over hundreds and hundreds of years, but wild rabbits are still wild and they will never be happy or satisfied living an indoor life. In the event of injured, ill, or abandoned babies, professional wildlife rehabbers or rescuers should do the work of helping them -- an inexperienced person is more likely to do more harm than good. Domestic rabbits are most comfortable between 50-75F (10-23C), but this may not be true for cottontail rabbits.