If you’ve ever been at the finish line of a marathon, you’ve probably seen the runners immediately wrap up in what appear to be tinfoil blankets. No, they aren’t warding off the aliens but rather protecting their body from a rapid temperature drop that often happens when they stop running.
Emergency blankets, also known as solar blankets, space blankets or mylar blankets are an essential item to keep in any good survival kit or bug out bag. An emergency blanket can be used to keep a person warm and shielded from the elements when their gear is either non-existent, insufficient, or compromised.
First developed by NASA (hence the ‘space blanket’ moniker) in the early 1960s, emergency blankets are made of a thin film of plastic coated with vaporized aluminum. This inner metallic layer allows one to capitalize on the heat the body naturally generates by reflecting up to 97% of the heat back toward the body. The plastic outer provides a protective, weatherproof layer to keep the person dry, helping him to retain even more heat.
Emergency blankets are a standard item in first aid, emergency response, and survival kits because they are wind and waterproof, effective heat retainers, and very inexpensive. They are also compact and lightweight, making them easy to carry. A typical space blanket costs about $4 and weighs about 3 oz. so carrying more than one is easy, cost-effective, and smart.
Some thermal emergency blankets are reinforced with an extra layer for added warmth. These reinforced space blankets are slightly larger and a bit heavier than the standard emergency blanket but offer better thermal retention properties and may be used as sleeping gear in extreme environments.
Some emergency blankets feature a neon orange (or other brightly colored) outer layer making them highly visible even in inclement weather. This visibility may aid in search and rescue or recovery efforts.
Emergency blankets are typically tightly compressed and packaged in a little bag or sleeve. They are extremely lightweight and compact, making them very easy to carry. However, they tend to be difficult to refold and repackage into the manufacturer sleeve or pouch. Emergency blankets are not ultimately designed for repeated use and heavy wear and tear. Durable enough to be effective, they must be properly cared for and carefully refolded after use if you plan to use them again and again. Small bags such as Coghlan’s Waterproof Pouches or even a large Ziploc may be useful for protecting your emergency blanket to preserve it for repeated use. The reinforced thermal blankets mentioned above also tend to be a bit more durable than the regular emergency blanket, holding up a little better to repeated use and folding.
Emergency blankets have more than one use as well – another quality we love in survival gear. Of course the primary purpose of a solar blanket is to keep warm, they can also be used to create a temporary shelter, signal for help, and even to keep cool. In their primary function of warming a person, an emergency blanket is simply wrapped around the person to capture and deflect radiated body heat back toward the body. An emergency blanket can also be used to create a temporary shelter that will protect a person from the elements and also keep heat in. The reflective metallic surface of the solar blanket can be used as a signaling tool, reflecting light and signaling your presence to a search party. Although the primary use of an emergency blanket nowadays is to keep a person warm, it got its start for just the opposite purpose. When NASA’s 1970s Skylab space station began to overheat in orbit the astronauts and engineers looked to a metalizing company in New Jersey to create a giant parasol for the space station that would reflect the heat away and allow the space station to maintain normal temperatures. And so, the space blanket was born. Of course the possibilities of other applications for the technology were quickly realized and solar blankets became the popular must-have survival gear that they are today.