Just a warning. If you are bitten on a gumboot by a snake, take the boot of very carefully and throw it away. It is possible that part of the fang is still in the boot and can work to the inside of the boot. Some venom can still be on the fang ......
With most venomous snakes fangs measuring at less than 2mm, I seriously doubt that fang being able to even get through the boot, unless your wearing very thin gumboots (would be more like rubber socks).
secondly, you are not likely to know a snake has bitten your boot (unless you saw it happen) as you would not feel it.
Thirdly, this fang would have to be sticking out far enough to actually scratch you to cause an envenomation, highly unlikely, you would have to be THE most unluckiest person to get an envenomation from a fang that is stuck in your gumboot.
Its more likely that a spider could drop down your boot through the top whilst walking through the grass.
But important note dont forget to always empty your shoes and boots before you put them on... critters do like that warm inviting cave that is created by your footwear.