Why does 60º F (15º C) air feel pleasant, but 60º F (15º C) water feels cold? And why, for that matter, does that same pleasant air temperature feel freezing indoors? It all comes down to the way heat escapes and is absorbed by your body. As long as the temperature of the surrounding medium (air or water, most often) is lower than your body temperature, you'll give off heat, and vice versa. The amount of heat your body gives off and how fast it happens depends on how good of a conductor that medium is. Just like a metal spoon absorbs more heat from a piping-hot soup than a plastic spoon, water absorbs more heat from your body than air because it's a better conductor. Heat escapes your body much faster in water than in air, so it feels colder to you. The fact that 60ºF feels chilly indoors and comfortable outdoors, however, comes down to radiant heat. Outdoors, energy from the sun is constantly around you, whether you're in direct sunlight or it's being filtered through clouds. Indoors, there's no sun, and the constant air flow from a building's HVAC system adds insult to injury by accelerating your body's heat loss. We've collected some awesome videos on this topic. Watch them now to learn more.