Honestly?

100°F (37.8°C) is universally uncomfortably hot 0°F (-17.8°C) is universally uncomfortably cold. 50°F is exactly what you'd expect it to be, 10°C, and room temp is ~70°F (21.1°C). Honestly it makes a lot of sense compared to humans (and most mammals).

People exist in both extremes but there's virtually nobody that could survive constantly in either temperature without taking measures and I'm willing to assert that as fact. Both are extreme but common. Thus I'm willing to call them a good general measure.