Snake bites can be VERY UGLY! Do a google search for snake bite photos and some of them will blow your mind. A factor in the severity of a snake bite would be the amount and type of venom you are hit with. Some snakes may bite without giving you a full load of venom. Some snake's venom is more destructive to tissue than others.
Some of the photos I looked at were pretty nasty. Water moccasin and rattler venom appears to be very destructive to tissue. Sometimes the swelling is so great that the doctor will make an incision down the lenght of the arm, leg, etc. to relieve pressure from swelling and to irrigate the tissue. Very nasty looking stuff.

Down here in the coastal plain of S.C. it is very common to see many moccasins, copperheads and rattlers during deer season. Season starts in mid August and runs thru first of January. Most of us wear snake boots, some all the way thru to January. I have seen snakes out in December some years.

On a personal level, I've know 3-4 people over the years that have been bitten. One guy lost his thumb to a moccasin. In dry summers I've seen water holes that are almost dried up literally crawling with 15-20 moccasins using the last little bit of available water. I've got a photo of a moccasin my brother killed years ago that was 54" long and 15" around. Rattlers up to 6' are pretty common.

Heck, if the snakes don't getcha the skeeters shore will!!!!