I am not familiar with the reptiles around the world. I can however, share the results of my (informal) research (read: googling) of several years ago. I did that, because I was going alone in the summer forest several hours from help at any time.
I discovered a viper incident report, among the many forum statements that snakes in Bulgaria are not deadly. So here is a summary.
A guy was picking strawberries in Rila Mountain, when a viper bit him on the hand. He squeezed some blood out of the wound and drunk water from the nearby spring. He later reported that the icy water made him feel better. His several companions helped him down to their nearby cars. There he received various medications and was wrapped in blankets. He was feeling well, but his eyes had already too slewed for him to open them.
He was transported to a hospital where, after several days he was able to open his eyes, and after several more was able to leave. As far as I remember, the only treatment they gave him were general infusions.
Unfortunately the text is in Bulgarian, plus I haven't been able to locate it for a couple of years.
Based on this, my conclusions were:
- if possible, purchase venom extractor (they are cheap).
- a poisoned person cannot walk significant distances (above 20-30 min).
- loss of vision is the most significant danger.
Therefore, I constructed a plan of how to act in case of a snakebite and replayed it in my mind for many days, until I could tell the steps without hesitating - drunk, sleepy, tired, thirsty - regardless.
It was something like this:
- Try to squeeze the blood out of the wound. (1 minute)
- Do NOT make a tourniquet if you are alone and are unsure of taking it out later. If within a group WedaPashi's advice would be better. (0 minutes)
- Take the tent out of the backpack and pitch it (5-10 minutes).
- Enter the tent, take out clothes, water and food out of the backpack. (1 minute)
- Put on all the clothes, pitch the bedroll, place the water and food close to your face. (5 minutes)
- Lay over my sleeping bag (if it is daytime, it would be hot), do not panic, try to dial someone from a mobile phone, don't expect to succeed.