I agree with Claire Senft; air-condition the darkroom. Even the smallest cheapest unit will do the job. You will be in there for hundreds of hours and you will use up thousands of dollars worth of sensitive materials. If you are addle-pated with heat and humidity you and your work will both suffer in ways that cost more than a tiny air-conditioner.
Sure enough when I built my new darkroom the air-con was central to the design. When heat wave conditions prevail I actually contrive to spend the day in the cool darkroom...ah, sybaritic bliss!
As for hot tap water, I've given up the fight. Modern films are surprisingly resistant to high temperature processing. A favorite easy to remember combination I use is Fomapan 200 in Xtol, 32 Celcius, 3 minutes 20 seconds; works a treat and the emulsion never melts or floats off.