Quantum leap

Suppose you had a dog whose personality fluctuated with the weather. On cool, crisp mornings, he's a champ, fetching, rolling over, and shaking hands at your slightest command. But as the sun climbs higher and the day warms up, he becomes less and less responsive, and you have to ply him with doggy treats to get him to obey. And during heat waves? Forget about it-he barely plays dead unless you double or triple his kibble ration.