What happens if the world gets too hot for animals to survive?

This is written by Matthew Huber, one of the Perdue professors who described the wet bulb temperature/humidity point. https://en.wikipedia.org/wiki/Wet-bulb_temperature

> As animals are moved by global warming outside of the environmental envelope that has encompassed them for literally millions of years, it is quite possible they will not have the ability to adapt. The best solution of course would be to avoid this experiment entirely. That is within the realm of feasibility. Limiting warming to less than 3 degrees Celsius by slashing the use of fossil fuels substantially reduces the area of the planet subject to dangerous moist heat stress conditions.

> One may rely on either natural or man-made refugia, or, in other words, moving populations of endotherms either uphill or away from hot humid regions, or building giant air-conditioned enclosures, in order to allow animals to continue to survive. But, if humans are in the position of doing this in a big way, that already presumes the fight to preserve the major ecosystems that make our world beautiful has been lost. For the sake of all the animals, including us, I hope we choose a saner path.