Floridians have a different definition of the word "cold." I live in Florida myself, and my brother-in-law, a resident of Illinois, visits ever November and frequently in February. He is fond of coming out to the back porch with a cup of coffee in the morning and loudly announcing, "Brudda, I just LOVE your cold fronts."
There are some legitimate concerns regarding penetration and expansion when a bullet has to penetrate several inches of clothing before impacting flesh. It is going to be going at least somewhat slower and a hollow point may well be plugged by the time it reaches the first layer of skin. This just isn't a Florida problem, though.