I don't get paid enough to sweat like a pig, plus I simply cant sleep when it's so humid/hot you can barely breathe. Might want to change companies if they don't let you idle at 70+ temps or have some ridiculous fuel bonus requirements. It was 91 in Texas today and I started sweating 2 minutes after the truck was shut off. Screw that.
My company has older CNG trucks without APUs, and newer diesel trucks with APUs. I’ve driven both kinds, and they let us idle the CNGs if we need a/c or heat.
If you really insist on going without an APU you’ll have to get a generator. You can get a generator that will run a portable AC unit that you can buy at Home Depot. The generator will run you about $300 and you can bolt it down to your cat walk. The portable AC has tubing for the exhaust. You can rig this up to exhaust out your front window and place the portable AC between the two front seats. The AC unit would need to be plugged directly into the generator.
All this advice seems to only apply to O/O's, not company drivers that are limited in what they can do with their truck.
Thermoking in Phoenix or Tucson sells them. Refurbished ones. My truck came with a tri pac. I had everything except the engine rebuilt / replaced. Was like $4,000.00 Paid for itself many times over.