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Wonder what the range of survivable temperature for humans is like compared to, say, cockroaches. Seems like it’d be a lot narrower
Without heating or air conditioning, it's not great, but just clothing and shelter which we've had for many millennia are good for -40°C to +40°C. Cockroaches are rubbish at low temperatures, you can kill them in a domestic freezer. Some invertebrates can survive excursions down to -80°C, but actually living requires temperatures well above freezing.
...as easy as you think. Humans are very adaptable and omnivorous. As long as something is alive on earth, there will be people around to kill it and eat it.