I remember hearing that the Thing was sorta vulnerable to electricity, in that it will instinctively attack whatever zaps it even if it would be in it's best interest to remain undetected. In the movie, they attempt to use a defibrillator on some dude who turns out to be a/the Thing. If it had just played dead, or pretended to "get better", it would have been fine. Instead it sprouts a set of jaws from it's ribcage and reveals itself only to get roasted.
So perhaps that's the Thing's major weakness. That and enough fire or acid will destroy anything made of organic matter.
True, for fire/acid resistance I was thinking of carapaces/exoskeletons and the like. I think that Norris-Thing was kinda fucked up from having a heart attack and was having trouble coordinating or something - a Thing's brain
is its body, not just the brain, so a malfunctioning organ would screw the thought process over and leave it to it's instincts. That mainly came about because it never expected to have a body part that was
broken, considering that that's impossible for it.
Didn't they use a heated piece of wire on blood samples to tell whether someone was the Thing?
They did. The blood screamed, IIRC.
It also jumped out of the container and later flowed away, which I'm not even sure how that's possible. It's CELLS can jump!