Keeping astronauts cool and comfortable on the baking surface of the Moon presented NASA's designers with a formidable challenge. How do you get rid of excess heat when you're standing under an open sky with literally nothing between you and the blazing fury of the Sun? One certainly can't open one's shirt. And no matter how vigorously an astronaut waved a fan under his chin, there would never be a cooling breeze.

So NASA developed the liquid cooled garment to keep the explorers as comfortable as possible on their jaunts.

Think of it like an electric blanket in reverse. A special set of long underwear in the suits contained a layer of thin water tubes that covered the astronauts literally from head to toe. A pump and refrigeration unit in the backpack regulated the temperature and kept the water circulating.

This technology is still in use in NASA suits today. When shuttle astronauts step outside to rescue a crippled satellite, or do construction work on the ISS, they're wearing the latest version of the cooling underwear first designed in the 60s.