Earlier quoted context omitted.
Not to mention, hot water tanks are a prime facility for some of these pests to grow while most people have no idea they should avoid their home hot water for anything other than washing. It should not be consumed in any way... this is why coffee makers specifically tell you to use cold water.
Pretty sure that is because of metals. Living things die when boiling anyway
Also, this might be a fun read for you: https://en.m.wikipedia.org/wiki/Thermophile