Answer:
When temperatures go too high, the animals in a population could experience hyperthermia -due to inability by the body to loss excess heat- resulting to death of some individuals who are unable to tolerate the high temperatures. When temperatures go too low, again, some of the individuals of a population may experience hypothermia- due to body failing to generate critical heat for the body- resulting in some deaths. Very low temperatures may also freeze water and make it unavailable for hydration. Optimal temperatures allow the population to thrive.