Norton smiled thinly. "Probably both. This space can isn't collecting any heat. We're too far from any sun. And there aren't enough people in it to keep it hot."
"Huh?"
"The average human puts out an average of about a thousand B.T.U. per hour over a twenty-four hour day. It rises in activity and falls with relaxing. But this can needs about five people to keep up the heat against the black body radiation from the hull."
"What do we do? Freeze?"
"One thing we can do. We can use the pedal generator."
"For what?"
"Two things. One is to charge up the energy cells. The other is that a human body in vigorous work can deliver as high as two thousand B.T.U. per hour. Although I doubt if any human body can keep up that kind of vigor for a full hour. If you're cold, you can easily warm up, Andrews."
"Why doesn't this tin can have a small pile?"
"Why doesn't a steamship lifeboat have a turbine?"
"I've seen some very small piles and generating gear."