After over 5 years experience...
I believe controlling humidity has done much good for my cats. It is
easy enough. Buy a couple of dirt cheap humidity sensors from the local
megastore (multiple meters provides more accuracy). Then use your air
conditioner, maybe in combination with an inexpensive dehumidifier, to
keep the humidity at no more than about 50%.
Fleas cannot propagate unless the humidity is over 50%. It has helped
with skin conditions, possibly due to lack of fleas. And then of course
there are benefits to human beings. Fleas can check in, but they don't
check out