Question

If microbes can live in harsh weather like very cold or very hot
than during the boiling why the microbes are killed by the heat ?

Answer 1

Bacteria may grow across a wide range of temperatures, from very cold to very hot. A mesophile is an organism that grows best in moderate temperature, neither too hot nor too cold. All human pathogens are mesophiles.

Since human pathogens prefer moderate temperature ,they will be killed at high temperatures (while boiling)

Microbes living in extreme conditions are another category,. that prefer extreme environments are known as extremophiles: those that prefer cold environments are termed psychrophilic, those preferring warmer temperatures are termed thermophilic or thermotrophs and those thriving in extremely hot environments are hyperthermophilic.