when I lived in Vietnam years ago, my Mac laptop fan broke and there was nowhere to repair it ... there are cooling pads with fans beneath them that you can buy, but my temporary solution was freezing a stack of Wired magazines in the freezer, then putting them under the laptop and changing them every 20 minutes.
This comes with its own set of problems though: I've done something similar and the mechanical stress from difference of temperatures caused the motherboard to crack.
It was one of those Titanium G4 beasts. My gf called it the "war machine" since the keys were worn to the point you couldn't read most of the letters. So it got way too hot before it even throttled down, and I never saw it shut off from the heat. It radiated heat through that metal... it would almost scald your legs.
I could usually control my CPU use so a magazine could last up to half an hour... but basically I'd feel the warmth coming through the magazine, jump up and switch it with another one from the freezer. Easy peasy.
I use a USB fan and a small mister/spray bottle of water. I spray my forearms periodically (top of hands are fine too I guess) and this creates more of a cooling effect from the fan.
It's also nice to have a wet cooling towel for the neck, I find...I tried one of those dual neck-mount fans as well, and while it wasn't bad, when it broke I didn't feel it was good enough to replace.
There are lots of whole-body tricks as well, from extra hydration (at least 100 oz. daily here in summer) to sitting on a cushion with more air flow...good luck.
One of those gel wrist rests, with added cooling, would be perfect. Lots of bloodflow just under the surface of the skin there. Would adding Peltier modules be a practical solution?