Quote all the science speel you want but it doesn't happen. It is an old wives tale. Lol
In winter time often I'm working away and the water will freeze like a sheet of ice on a conservatory.
According to the science speel then that's me done for. Hot water will only make things worse? WRONG.
I go back to the van, fire up the boiler, wait for hot water to come through to the brush head, and I can then melt off the ice I previously created, and then continue on with my day.
I've worked up to -6 before with no problems.
Science schmience.
I think the theories are more related to boiling water. Not warm, and possibly very very sub zero temperatures. Who knows.
I've got real life experience with this and trust that any day over Wikipedia.
