i lived in a sweat lodge of a factory building for years. it was a brick kiln, black membrane roof just above my head, and
a vented skylight so all the building's hot air vented through my space ... it was fun
vpwphoto makes a great point, to have a bunch of water just in buckets at ambient room temp. ...
but if your ambient temp is kind of high ( summers mine was between 80-90º, and cold water was between 70-80ºF ) it will only do half the job
... if you store water to mix your chemistry in your fridge, that will help ...
small hand-tanks don't take a lot of water to wash, especially with fixer remover ... you should easily be able to
do a final wash with a a supply of 2.5 or 5 gallon buckets to do your final wash ( and it doesn't really matter if your wash water isn't 68º ) ...
for developer, fix, stop, fix remover, you can mix fresh with water you have stored in the little fridge ...
and if it is too cold you can mix it with your gallons in the buckets or with warmer water from your spigot
if you find your film developing to be too short + uneven negatives ( below 5-6min? ) ... you might also thinkabout developers with glycin in them like to be used at around 72-73ºF ( lots of formulas out there, and the photographer's formulary sells + makes glycin )
and also look around for formulas for "tropical developers" ... they also like hot temperatures ... the formulary sells the chemistry to
make them ..
making developer from component chemicals is pretty much the same as mixing a dry packet of your D76, except you mix
4 or 5 things together, instead of 1 ...
have fun ( and good luck) !