@donc @zande @JENGOSMonkey
I would assume that Basenji's, coming from Africa, Zaire or Congo, and being short-haired, tireless, doubles suspension trot, are genetically predisposed to handling heat better than most dogs, and this would be manifest in panting less, since panting is to dissipate heat. (Of course, as suggested, that doesn't mean this breed cannot get overheated, as indicated by those with experience seeing a "pinched" look when they appear hot.)
My cockapoo loved to run as we mountain biked, and of course, he panted up a storm. He loved to get into the creek or mudhole to cool off. Oddly, he would never drink a drop of water from a dish or bottle, only the creek (just a few laps), but drank mostly after getting home.
That basenji's would have higher tolerance for heat than most other breeds is an unsubstantiated assumption on my part based on info anyone can find on the internet, not from a peer-reviewed expert source. I can't seem to find any such books written specifically about the basenji. Suggestions?