Give him a flea bath with a good flea shampoo. Kittens are very easy to bathe, all ya do is scruff him by the neck and wet him down. Lather him up and let the lather sit on him for 5 minutes. Then rinse. Do that a couple times and you'll see the fleas bailing. I thought Revolution was okay for kittens over 8 weeks old. I would NOT buy any over the counter remedies, but call your vet. He might want to see the kitten to make sure he's not anemic from the fleas. Fleas are a potential danger to young kittens.

Good luck.