Sometimes Hot, Sometimes Not!

While an energy-efficient air conditioner may keep you cool indoors, the idea of strapping an air conditioner on your back when facing the heat outside is impractical. And for some people - combat soldiers, fire-fighters, or even the folks who dress up as costume characters at theme parks - too much heat can be deadly.

For years, researchers have worked on the problem of creating " micro-climate cooling systems " to keep people comfortable in uncomfortable temperatures.