I come back to the heat treatment.
Many venoms are active by their protein's content, like different toxins, enzymes... Those are biologically aggressive because they have the exact form / structure to react with important cell components. each one is a very specific reaction, so if you can modify their structure, they don't work any more. Often (but not always), those proteins are heat sensitive. To visualize that, you can look at a cooked egg or steak. Hopefully, they loose their active form before most of our cell proteins.
Apply warm water, or some heat source, as warm as you can stand and enough time in order to warm up (deeply) your skin. Try to not burn yourself, though. Just do that as quickly as possible after the bite to avoid the spread of the venom.
Some of your own proteins will be degraded too, but you can make others for replacement. To give an idea, the first degradations come around 53°C (but your nerves send you some strong messages before that). Try to get around this temp and the venom's proteins become "cooked" before your flesh.
That way, the venom is still here, but no more active. It's just some trash the body has to clean now, no longer harmful.
For the possible infection, it's an other story but it's rarely an emergency.
