It’s always strange to me how the body prefers 72 to 75 degrees F on the outside but 98 F on the inside. Anything approaching equalizing of interior with exterior temperature results in heat-related illness.
We basically run on tiny combustion engines. Exothermic reactions.
We aren’t a passive 98 degrees, we would be hotter if it wasn’t cool enough outside. Higher heat would cause different cellular structures to become misshapen, leading to system breakdown. I’d be like trying to run a cpu cooling loop with boiling water.
And I’d add to that that if our thermal dissipation is overwhelmed, our internal heat build up. To do that heat dissipation, we need to have an environment that suck out more heat out of us than what we produce. If the environment is too hot, the heat build up and as Deadrek says, our internal inner workings beak down.
That why we sweat. Water suck out a lot more heat than air, because it wants to saturate the ambiante air, and to do that it suck up our body heat to become steam. Rince and repeat (literally).
But once the air is to humid, it gets more and more difficult for our sweat to evaporate, which makes it ineffective. That why we can kinda survive in a 90°C + sauna (albeit not for long, but for a different reason), but not in a 37°C (98°F) 100% humidity place like some tropical rainforest. At least, not without specialized acclimatation and survival techniques.
I mean, thats kind of like arguing that the exhaust is the cooling system for the car, which, undoubtedly much heat is lost through the exhaust. But that isn’t the princpal way it loses heat; the radiator is, and the radiator is much more akin to say, our ears, which are external, and the fluid moves through (rather than being ejected).
Yeah, but my point was that its a fundamentally different kind of heat transfer.
Its the difference between how an oven cools itself and how a power plant cools its self. With an oven, you vent the hot gas that is created through elsewhere, moving the gas and the heat away from its source. That gas (fluid) isn’t re-used. In a radiator, the fluid is re-used in the cooling loop.
A car or a power plant or the human ears are that second example. We’re heating a fluid (blood, radiator fluid, water, etc), to transfer heat to secondary fluid (air, more water, etc…). With a power plant, you have fluids in a circuit, transferring heat from one to the other. The primary cooling fluid doesn’t leave the circuit.
In the first example, we’re ejecting the hot gasses directly, and not re-using them as a fluid. This is more like a car exaust, or an oven, or human breathing.
Its in-out cooling versus around-and-around cooling. Humans (afaik) are primarily cooled through in-out cooling. We do radiative heat transfer and have organs adapted for that specifically, but its a very small amount of heat transfer compared to what we get from in-out cooling.
A car also has both radiative and in-out cooling. But it gets far more of its cooling from its radiator than it does through ejecting hot gasses.
Human cooling is mostly us throwing away hot gas, and we don’t reuse it. We get some cooling through our blood, but less than what we get through breathing.