Why was the Apollo 13 crew feeling cold (in the movie)?

It is indeed hard for objects in a vacuum to lose heat—compared to objects in the air. Without air to conduct and convect away heat, objects in space must radiate heat energy in the form of infrared light. At the temperatures humans find livable (as opposed to space heater temps) that's a slow process. read more

To get the Apollo 13 crew home, the LM would have to support three men for 3.5 days. Food, water, oxygen, and power. (Power was used to run the communications stuff, mostly.) The LM batteries had 1800 amps total. That had to power a ship for ~100 hours to get the three astronauts home — alive. read more

Apollo 13’s original crew of Jim Lovell, Ken Mattingly and Fred Haise with an unidentified person. Credit: NASA The carbon dioxide filter: In the movie, as the crew faces a deadly buildup of carbon dioxide, a team in mission control builds a new system on the spot that adapts an originally incompatible filter. read more

Apollo 13 was supposed to land in the Fra Mauro area. An explosion on board forced Apollo 13 to circle the moon without landing. The Fra Mauro site was reassigned to Apollo 14. read more