Asymptomatic

I was driving Riley home from karate when he asked me, "What if the Earth was 150 degrees all the time?"

There are two answers to this question, and one isn't very interesting.  I went with the second, more interesting one, "If it was 150 degrees all of the time, then when life evolved on this planet, it would have evolved to survive in 150-degree weather.  ...  It probably would have looked a lot different from what you see around here today, too."