...what physical changes would you make to humans and why? (I beg you, please try to keep suggestions at least half-sensible) It always annoys me that when I cycle in cold weather, I am too warm from the exertion, and yet my hands are freezing. I'd give the part of the brain that controls thermoregulation the ability to compensate for temperature differences around the body. If the body is too warm but the hands and face too cold, then rather than divert blood away from the extremities, making them colder and the rest of the body warmer, it is fed towards them so that they are warmed and the blood flowing back to the warm areas is cooled. Problem solved!