I was thinking the same thing about chlorine and/or chemicals. As far as their hair, I guess it would be okay if the didn't stay in forever and you washed it out with a good shampoo and conditioner. I'm sure the stuff in the water plus all the heat and additional hair drying and stuff would dry out their hair just as it does ours, I guess. I was also wondering about their ears getting bothered or infected from too much water, chlorine, or even the salt and sand from the ocean? I don't know, maybe I am overthinking!!