Mylar survival blankets, or space blankets as they are sometimes called, are one of those ubiquitous items that show up on every prepper checklist.
These shiny blankets are supposed to keep you warm in pretty much all conditions, or at least warmer, even if you do wind up looking like a baked potato. These are some pretty serious claims for what appears to be some very simple technology.
Do cheap survival blankets actually work?
Yes, mylar blankets will indeed keep you significantly warmer than you would be otherwise, although they are not infallible, and proper technique is required to get the most out of them. Used intelligently, they can reflect a significant amount of heat back on to the user.
In the rest of this article will provide you with more insights and tips for getting the most from these inexpensive, crinkly but effective survival blankets.
Survival Blankets Really DO Work
We need to clear this up because there are still some uninformed naysayers out there. Survival blankets really do work.
No, a piece of equipment does not require a substantial insulative value to keep you warm. There are other principles at work that result in a net gain of heat.
It is hard to believe that something so small, so affordable and so compact would be worth anything except as a solution for wrapping up your leftovers, but it is true.
These blankets were originally engineered by NASA, people who know a thing or two about science, and they are a constant sight at scenes of accident, disaster and other events of physical mayhem where victims and first responders need to keep warm.
They are absolutely legitimate, and so long as you use them properly they do have value! They aren’t the end-all, be-all answer to all problems of warmth and shelter, but nothing is.
They are tiny, light and affordable, perfect for keeping in BOB’s and vehicles. Get several!
The Secret is Reflection
The shiny, metallic surface of a mylar survival blanket is the key to its function. So why do blankets help keep you warm based on the principle of reflection, not insulation?
In short, and without delving too far into the hard, crunchy science of it, heat is reflected from shiny surfaces. When you wrap a survival blanket around your body, the heat radiating off of you strikes the shiny surface of the survival blanket and bounces off, back toward your body.
As it turns out, reflected heat energy works very much like other forms of radiant heat and helps keep you warm, or at least warmer!
You can supercharge this principle in action by using a survival blanket unfolded and spread out as a large, flat reflector, placing it behind you and then sitting between it and your campfire.
Your survival blanket will reflect an amazing amount of heat off of the fire back on to you, keeping you totally warm all over!
But they are “Leaky”
Survival blankets are not perfect. They aren’t a tent or bivy. They sure aren’t a nice inclement weather-rated sleeping bag. Survival blankets are often described as “leaky”, because they are not particularly insulative.
Any wind will easily get between you and your flimsy, ultra-thin survival blanket, robbing you of the precious heat you are trying to accumulate. Similarly clammy, wet clothes or skin won’t dry out so quickly just on account of a survival blanket.
If you are in some really nasty conditions simply wrapping yourself up in a survival blanket and sitting there, hoping for the best, might not even ensure you maintain enough warmth to survive.
You might need to keep moving in order to keep your blood flowing and your muscles working, raising your heat even more. You might have to get in out of the wind and rain to shelter before relying on your survival blanket to see you through a cold night.
This can be mitigated somewhat by rolling up or wrapping yourself up in the survival blanket as tightly as possible. Ultimately, they are another tool to help you stay warm, not a magic spell that will always keep you warm.
They Can Also Be Fragile
Speaking of inexpensive survival blankets the assertion that they are little more than lined aluminum foil is oftentimes a fair insult. Cheap survival blankets are just that, cheap, and usually in the bargain you’ll give up durability.
Many of the least expensive options on the internet and in stores will tear with very little effort or provocation, reducing their effectiveness and eventually turning into a run that will destroy them.
This can be exacerbated if they are used as a ground cover or you are putting them under tension in order to use them as a large reflector.
Disclosure: This post has links to 3rd party websites, so I may get a commission if you buy through those links. See my full disclosure for more.
Buy the Best Blanket You Can
Survival blankets are sometimes thought of as throwaway items because they are so affordable, but like any other piece of survival gear you should spend enough to assure you get a quality product capable of doing the job you’ll need it to do.
An upgraded survival blanket will still be quite affordable by most people’s standards, and usually have features that can make the difference.
These nicer examples usually feature higher quality construction that is significantly more durable, a foil surface mated to a wind and water impermeable core and a nice outer hem with grommets that helps keep the whole thing together while making it easier to hang, fold and store.
Cheap survival blankets absolutely work, helping to keep you warmer than you would be without one.
They tend to be on the fragile side, and they don’t do a very good job of bucking the wind, but their usefulness as an additional layer or full-size reflector makes them invaluable and all kinds of situations and they deserve a place in every prepper’s survival stash.