Antivenin needs to be kept refrigerated.

It is very expensive these days, about $350 per dose, and sometimes you need several doses. (in the mid/late '70s, it cost about $19 a dose, IIRC.)

Some people are allergic to the antivenin. Doctors do a sensitivity test before they give the big dose.

Working for a vet in southern California for 12 yrs, we saw quite a few rattlesnake bites; once, three in one day (our record!). Nothing I've ever seen on TV or online shows what it looks like a day or two later. First the area swells enormously, turning darkish red. Then the skin starts to die and turns black. The dead skin eventually sloughs off. Of course, the area is usually bandaged to keep it clean. It takes quite a while for the skin to granulate in. People sometimes need skin grafts.

You are simply in no position to treat a snakebite without professional help. And there can be several variables: Some bites are what they call "dry" bites with no venom, as the snake can control how much venom they inject; it can depend on how big the bitten person is, and where they were bitten. A dog bitten on the tongue will probably die of suffocation. A person bitten in a vein may die in fifteen minutes. The quicker you get to help, the better off you'll be.

Avoidance is better than treatment. In snakey areas, walk with a staff, and poke it into areas when you want to put your hands or feet. Walk heavily. Snakes don't smell or see very well, they depend on vibration to tell if prey or a threat is near. Most American snakes usually only strike when they feel threatened or cornered, and are willing to leave the immediate area, given the chance. I don't know about foreign snakes.

Rattlers usually stay in the shade during hot weather, and come out into the open to bask on warm paths, roads or rocks when the sun goes down. Carry a flashlight and watch where you're walking.

Children are most at risk because of their small body size, and tend to require more antivenin. Teach your children not to put their hands in holes and out of site ledges. And teach them NOT to tease snakes. A big rattler has a pretty good striking distance.

I've spent a lot of time in the desert and have only seen three rattlers, and most of those when I was sitting quietly on a rock.

Baby rattlers can be as dangerous as their parents, simply because they can inject venom, but they don't have (enough) rattles to rattle in warning.

And you know that business about shaking out your shoes and clothes before putting them on in snake country? Well, it's true. And even if there aren't any snakes, it helps to unload the scorpions.

Fallacies:
A snake that has bitten someone can't bite anyone else until his venom builds up. Actually, they can bite several times, as they can adjust how much venom they want to inject.

A snake whose head has been cut off can't do any harm. In reality, they can still do a convulsive bite, but tend to put more venom into it as control is not an issue.

An old pair of boots with snake venom or a snake's teeth in it can't hurt you, as the venom loses its strength when it dries.

A tourniquiet to stop blood flow is not the same kind of tourniquet that used to be recommended for snakebites on a limb. Unless the venom went directly into a vein or artery, the venom will be transported by the lymph system, not the venal system. If you put a tight tourniquet on a snakebite victim, you will kill the limb. John Wayne was never a doctor, his directors didn't know diddly about snakebites, and everything you've seen on TV and movies about treating snakebites is wrong. (How's THAT for a sweeping statement?)

Sue, who knows more about snakebites than electricity, by far