I really like this idea. The rubber scares me though. My first thought was of the pictures in my friend's fire science textbook. Rubber and synthetics near skin don't do well with heat. Leather is better protection against fire and heat, because it's not a sticky hot mess.
I also like the limited uses. I kinda like the limit being one use though. You touh fire or lava or whatever and then the item breaks after x number of seconds. Preferably with the tool breaking sound so you know its happened. Of course anything is programmable, but since I don't program I don't know how feasible it is to add a triggered time delayed item decay like that. Would be very cool though.
it's supposed to give you a free "Mess up" when you fall in lava. A time limit would be helpful.