R.S.
Last year when my daughter was also 3 months old we had a horrible flea infestation. You could not even walk into the living room without having twenty fleas jump on you. I couldn't get Aztec to come in fast enough so I read something on the internet about how fleas cannot tolerate heat. So we turned up the heater, treated the cats, and "baked" the house for 2 days. The temperature needs to exceed 90 degrees, I believe. Well, it worked and we never saw another flea in the house.
Good Luck!!
R. Sanders, ND