So, basically, endurance is 100% a predictor of win? So what if you can run 26 miles in a few hours. Cheetah is going to kill your ass before you can get 26 feet.
A lone cheetah is actually going to find it pretty tough to take down an adult human. They're about the size and weight of some larger running dogs, so you probably outmass it by fifty pounds; you have longer reach; cheetah claws are not terribly sharp and it lacks the brute "upper body" strength of most large cats. Unless you run from it, it won't be able to trip you; cheetahs are relatively fragile, being built for speed, and typically won't even bother with a full-body takedown manuver since it puts them at unnecessary risk.
Your only real risk is if you turn your back on it (while on the ground!), in which case it will do the usual cat thing and attempt to crush your spinal cord. (Which I assume it's capable of, but it may not be; cheetahs typically go after very lightly built prey and a human is out of its weight class, as mentioned before.)
I'm strictly here for the Fail Biology Forever bits.
I came up with something. Imagine if a creature could be both warm and cold blooded "could switch on and off its body heat production". If it gets too warm, the creature could turn its body heat down or off and back on again when it gets colder. It would be very adaptable and energy efficient. Just like if a creature could switch its visual modes from visible to infrared at will. Strange that no creature could ever accomplish that.
Congradulations, you've basically described the mechanism of warm-blooded creatures. The simple truth is we do such things all the time; our core body temperature is high as a measure of our ability to react and act quickly. We can, and do, self-regulate by turning off mechanisms that generate extra heat. That's why you aren't shivering all the time. Most of the rest is the natural function of the body and about as integral as breathing; not something controllable.
Also, there ARE things that see infrared. Most snakes are capable of sensing infrared. The common American white-tailed deer sees in black, white...and infrared. The human eye, for that matter, is slightly sensitive to infrared. You can get special sunglasses that block out visual light wavelengths to prove this, if you like.