On holiday in Southern California recently, I was on an evening tramp in the hills and stepped within a few centimetres of a rattlesnake's head. It was almost a metre long, and looked just like a tree root on the track. It didn't bite me but did almost scare me to death. What should have done if I had been bitten? - Jessi
First, as with any emergency, calm down. Panic breeds bad decisions and spreads the poison around quicker.
Sit somewhere safe and mummy-wrap the bitten region firmly but not tight enough to cut off blood flow. You can use a long cloth strip torn from a friend's T-shirt. The wrap works by compressing lymph channels, decreasing the spread of the venom in your tissues and bloodstream and delaying the onset of severe symptoms so you can get to an ER in time and get antivenom if needed.
If practical, have friends carry you out. If immobilisation isn't possible, do the next best thing and splint your leg with something firm like a stick or hiking pole. Then get yourself to a hospital immediately.
Scary as it might be, deaths from snakebite are extremely rare in the United States and Australia. In the US there are about 45,000 bites a year, with only 12 fatal. In Australia there are about two deaths a year which are often associated with alcohol use, provoked bites, and failure to seek prompt medical attention.
Bees and lightning kill 10 times more people each year than snakes. Many bites will be from non-poisonous species, and up to half of even the poisonous snake bites are "dry bites" where no poison is actually injected.
Pressure immobilisation is the single best thing you can do to help yourself. It replaces all the old techniques of sucking, cutting, shocking or putting a tourniquet on bites - all of which have been proven useless or dangerous.
Here's hoping you never need to use this advice.