To open the chest I just double click it, long as your suit is 70 fire it can't kill you.
True, for the most part - but there is a long-standing (at least 10 years running) bug with level 2 chests (only) where you can take obscene amounts of damage. I was once killed by 160 points damage opening a level 2 chest, with 70 fire resist. While I can survive opening level 1, and level 3-6 chests, that way, you're playing Russian Roulette with level 2s, hoping you don't have one of the bugged ones (and I've had it happen with paragon chests too - but can't remember if it was the ones with level 2 maps in them, or the ones off creatures that drop level 2 maps that have level 3 maps in them).
Buy telekenesis scrolls from an NPC Mage and cast from them. You can avoid taking the damage. On the higher level chests you may want all the hit points you can get.
Magery scrolls cast as 2 Circles lower than the normal spell. Telekensis scrolls will cast as a 1st Circle Spell. At 0.0 Magery you will have a 45.0% chance to cast it. The scroll is only used up when successfully cast.
Stayin Alive,
BG
Note that telekinesis doesn't work on Siege Perilous and Mugen, if you decide to try out T-hunting there, with the housing changes.
A human has an even greater chance of casting the scroll, if you've got someone handy to cast it for you. As a garg, with no strong back and the inability to ride a blue beetle during the spawn fight to keep it alive, it doesn't hurt to have a buddy or a second account around on a human for the higher chests, to haul stuff back (especially if you or the buddy unravel stuff for imbuing training on a different character), as around level 5 maps the chests start hitting amounts you can't easily haul off even if you send the gold to the bank with a bag of sending. I'll occasionally go out on my T-hunter to do multiple maps, and have my (also human) Tailor on my second account tag along on my second computer, far enough away to stay alive. That way, even if I only keep gold and the rares, I can stay out for about 6 level 5s or 5 level 6s, loading the gold into the beetle (for the first 240k - the remaining 60k split between the two), and have the marties, ingredients and rares split between the two character's packs so that I don't have to worry about weight issues on the T-hunter in combat.
Of course, I'm still a big advocate of group T-hunting, simply because you get big maps done quicker, but solo is worth the challenge.