I just normally take it up to a boil and turn the flame off and let it cool a bit while I'm continuing the rest of my bottling process. It stays near boiling for a few minutes whether the stoves on or not.
But please don't ever lose sleep over any aspect of this hobby there's a million ways to do things and usually they are all correct, and it is really hard to screw things up. Beer has been brewed for thousands of years, without the internet, without instruction books, with rudementry sanitization if any, and with little understanding of the process, and even understanding things like that yeast fermented beer, and STILL it managed to survive, and it manage to be tasty enough to have survived culturally, and not gone the way of pepsi clear.....it's really hard to screw this up.