A sleeping bag is a warm, padded blanket that zips up around you like a cocoon, designed to keep you comfortable while sleeping outdoors or away from home. Instead of regular sheets and blankets, you climb inside a sleeping bag and zip it closed, trapping your body heat inside the insulated fabric.

Sleeping bags became popular in the early 1900s when outdoor adventurers needed something portable and warm for camping trips. Modern sleeping bags come in different styles for different conditions: lightweight bags for summer camping, thick insulated bags rated for freezing temperatures, and everything in between. Some are shaped like rectangles, while others are mummy bags that fit snugly around your body to trap more heat.

You might use a sleeping bag on a camping trip in the mountains, at a sleepover at a friend's house, or even in your own backyard on a warm summer night. The beauty of a sleeping bag is that it rolls up small enough to strap onto a backpack, making it a perfect portable bed for adventures. When you're ready to sleep, you unroll it, climb in, and zip yourself into warmth wherever you happen to be.