A lady my wife got to know through election conferences lost her young son {4 or 5 years old} to a rattlesnake bite a couple three months ago. I forget which {Florida} county it was, but the boy was with his father working their melons when he was bit. I think he had other health issues, something about his immune system. A teenage boy here in Calhoun County got bit by a cottonmouth taking the trash out to the road. He was sick for a few days, but as far as I know, made a full recovery.
Back when we raised hogs on our woodland, they killed a lot of snakes. We would have a hog bit all along. Something about the fat around their face seemed to keep them from dying. They would swell up, but I can't remember one every dying. I've also noticed the more fat on a dog, the better his odds of surviving a snake bite. BIL lost his best Redbone to a rattler. {The dog was trained as a chicken dog, and since he was killed they have lost a lot more chickens to varmints}
The odds of getting snake bit, and of dying of it is so far down the list of things that can kill you, I give it very little thought. That said, I always look over logs before I step over. Most snake bites happen when you step on them or try to pick them up. Rattlers especially will leave an area with lots of people. They have learned that when they are seen, they get killed. Cottonmouths are a different breed, and have to be treated differently. Once in a while you will come across one who will do his best to get you. Anytime you are in swamps, always keep an eye out for them.
Larro