Term for maximum temperature value

Question

Objects falling in the earth's atmosphere can reach a terminal velocity in which they can fall no faster. Is there a synonymous term for objects heating up?

Answer 1

The “Planck temperature” is

$$ T_\text{P} = \sqrt{\frac{\hbar c^5}{G k_\text{B}^2}} \approx 1.42\times 10^{32}\rm\,K $$

Some sources refer to this as a “maximum temperature,” by the same logic under which the “Planck length” $\ell_P = \sqrt{\hbar G/c^3}$ is a “minimum length.” But it’s probably more accurate to say that, as the temperature approaches this threshold, there will be quantum-gravity things happening that we currently don’t have any model for. The Wikipedia page currently says

An object with the temperature of ($T_P$) would emit a black body radiation with a peak wavelength of $\ell_P$, where each photon and each individual collision would have the energy to create a micro black hole of Planck mass. There are no known physical models able to describe temperatures greater than or equal to $T_P$.

To my reading the Wikipedia prediction is overconfident; I think there is lots of room for new physics at lower temperatures.

You might like this old post about high-temperature plasmas.