Space blankets, often referred to as mylar or emergency blankets, are a staple in emergency kits and survival bags around the world. These lightweight, compact sheets are marketed as essential gear for survival in cold weather. But are they as life-saving as people claim, or are we relying too heavily on a shiny piece of foil? Let’s dig into the myths and realities of space blankets and explore whether they live up to the hype.
What Exactly Are Space Blankets?
Space blankets are made from a thin, reflective material known as mylar. Originally developed by NASA, this technology was designed to reflect heat, making it ideal for astronauts and now, survivalists. The idea is simple: these blankets trap and reflect your body heat back toward you, helping to keep you warm in cold conditions. They are often inexpensive, easy to store, and come in a variety of sizes.
Can They Really Keep You Warm?
The key selling point of space blankets is their ability to reflect heat. They don’t provide insulation like a thick wool blanket, but instead, they bounce radiant heat back to your body. In controlled testing, users have found that these blankets can increase the temperature around your body by up to 18 degrees Fahrenheit. However, the degree of warmth you feel depends on how effectively you use the blanket.
The Right Way to Use a Space Blanket
A common mistake people make with space blankets is improper usage. Wrapping it directly around your body, while seemingly intuitive, can backfire. Space blankets don’t breathe, meaning they trap moisture as well as heat. This can cause condensation to build up, making you damp and, eventually, colder. The correct way to use a space blanket is to place it over your outer clothing layer or sleeping bag, creating a heat-reflecting barrier without sealing in moisture.
What Space Blankets Can’t Do
While space blankets do an excellent job of reflecting heat, they are not magic shields. They won’t protect you from the cold if you don’t use them properly, and they certainly won’t save you in extreme weather conditions on their own. These blankets don’t provide insulation against cold ground, meaning if you’re sitting or lying on cold surfaces, the heat loss through conduction can still be significant. To truly stay warm, you need to combine the blanket with other forms of insulation, like pine boughs or an elevated platform.
The Wind Factor: A Major Weakness
One of the biggest drawbacks of space blankets is their vulnerability to wind. Because they are lightweight and thin, even the slightest breeze can break the barrier of warmth they create. In windy conditions, the blanket can become more of a hindrance than a help, robbing you of the heat it’s supposed to conserve. This is why many survival experts recommend finding or creating windbreaks before relying on a space blanket.
Durability: Not Built to Last
Most space blankets, especially the cheaper versions, are fragile. They tear easily, especially if they’re used as ground cover or exposed to sharp objects. This fragility makes them suitable for short-term emergency use, but not for repeated applications. Upgrading to a more durable, reusable mylar blanket with reinforced edges or grommets can make a significant difference in both effectiveness and longevity.
Emergency Bivvies: A Better Alternative?
For those looking for a more robust option, emergency bivvies are a step up. These mylar-based sleeping bags cover your entire body, keeping you warmer than a standard space blanket. While they’re bulkier and more expensive, they provide full-body coverage and better wind protection. In testing, users found that bivvies could increase body temperature more effectively, maintaining a comfortable warmth in colder conditions. They’re a good investment for anyone who wants a reliable emergency shelter.
The Importance of Fire
When using a space blanket or bivvy, pairing it with a heat source like a campfire significantly boosts its effectiveness. Space blankets can reflect fire heat back toward you, essentially creating a warmer micro-environment. Placing the blanket behind you with the fire in front reflects warmth from both sides, making a big difference in survival situations. Without an external heat source, though, the space blanket’s limitations become more apparent.
Moisture: The Silent Enemy
Another critical factor is managing moisture. Space blankets are not breathable, meaning sweat and condensation can build up quickly. In freezing conditions, this moisture can freeze, causing discomfort and, worse, hypothermia. If you’re using a space blanket, it’s vital to monitor your body’s moisture levels and adjust accordingly – ventilation is key to preventing the buildup of sweat inside the blanket.
Mylar Blankets: Cheap but Effective
Despite their shortcomings, space blankets have a place in any emergency kit. For the price, they offer a lightweight and compact solution that can make the difference between life and death in some situations. They are particularly useful for hikers or backpackers who want a lightweight emergency option that doesn’t take up much space. Having one or two packed away for emergencies is always a good idea.
Upgrading Your Gear: When to Spend More
While the basic mylar blanket is a good start, investing in higher-quality gear can pay off in a survival situation. Reusable mylar blankets, with thicker materials and additional features like grommets, offer better durability and more reliable heat retention. Spending a little more on a durable emergency bivvy or shelter kit can provide peace of mind and better protection in the long run.
Don’t Rely Solely on Space Blankets
It’s important to remember that while space blankets can help, they aren’t a replacement for proper cold-weather gear. In a pinch, they can prevent hypothermia or frostbite, but they’re not a long-term solution. If you’re heading into extreme conditions, always have the right clothing, sleeping gear, and shelter. Space blankets should be viewed as a supplement to these, not as a primary means of staying warm.
A Valuable Tool with Limitations
In conclusion, space blankets are a valuable addition to any emergency kit, but they are not a one-size-fits-all solution for survival. Used correctly, they can reflect your body heat and keep you warmer in cold conditions, but they need to be paired with other strategies like insulation, fire, and wind protection to truly be effective. Whether you opt for the cheap version or invest in a more durable option, understanding the strengths and weaknesses of space blankets is essential for anyone looking to stay prepared in the wilderness.
Mark grew up in the heart of Texas, where tornadoes and extreme weather were a part of life. His early experiences sparked a fascination with emergency preparedness and homesteading. A father of three, Mark is dedicated to teaching families how to be self-sufficient, with a focus on food storage, DIY projects, and energy independence. His writing empowers everyday people to take small steps toward greater self-reliance without feeling overwhelmed.