What do you consider "extreme" cold?

That's a terrifying thought. But then what happens when you get very old? We don't live forever. And even if some life extension technology is discovered before we die, what about everyone in the past who died? Did they all end up in a reality where some incredible technology figured out how to keep everyone conscious indefinitely? What about people who lived before we even knew what viruses were? As intuitive as it feels, it doesn't seem to pass the smell test. I would guess that some of the "intuition" I'm feeling is actually just a fear of dying

Quantum suicide is really interesting, I've always thought something like this could be possible and this is the first time I'm learning that there's a word for it. There's something intuitive about it, I bet lots of people also feel the same way. I've been in a few potentially near-death situations and one specific thought always pops into my head afterwards, "I wonder how many versions of me just died from that."