There are several different types of blankets that are suitable for prepping and survival purposes. Which type you choose depends on a number of factors: warmth, size and weight, suitability for outdoor use, and cost. You can spend under $10 or over $100 for a survival blanket, so price is an important factor. Let’s start with the least expensive options.
Mylar is a tough clear plastic, usually a few mm thick. When it is coated with a thin layer of aluminum, the combination is a tough reflective material that helps retain body heat by reflecting heat back to your body. This type of blanket is often called a “space blanket”, but it is very un-blanket-like. The material is very thin and waterproof, but not soft or warm to the touch.
Pros: aluminized Mylar is very inexpensive: under $10 for more than one “blanket”. It is thin and lightweight, so it does not take up much room in a survival kit or backpack. This material has proven to be effective at helping to retain body heat. It is sometimes even used in medical applications to keep patients warm.
Cons: It is thin, rips easily, does not conform well to the contours of the body. Cold air can get between the space blanket and your body. Aluminized Mylar is also flammable; do NOT use near a campfire or any open flame.
This version of a space blanket uses the same type of material found in plastic tarps, but with a layer of aluminum for reflectivity. So this would be the high-end version of space blanket. But the cost is reasonable, around $20. It rips much less easily, and has the same ability to reflect body heat as the Mylar version. It can also be used to make an impromptu shelter, or to place over damp ground for sitting or camping.
Pros: This product has all the advantages of aluminized Mylar, except that it is more bulky and heavy. Only get the aluminized Mylar if space and weight are at a premium. Very durable, multiple uses.
Cons: Like all space blankets, it does not conform to the contours of the body, and cold air can get between the blanket and your body. It is not soft or warm to the touch. Flammable.
Caveat Emptor — let the buyer beware! The quality of wool blankets that you can buy online is extremely variable. Some military surplus blankets have been stored in moth balls for years. Some wool blankets are made from “reprocessed” wool fibers. Other wool blankets are only 50% or 70% wool, and the rest synthetic. Prices vary from around $20 to over $200.00.
My advice: Avoid military surplus and recycled fiber wool blankets. These are less expensive, but also lower quality. You want “virgin wool” meaning new fibers. The best quality wool is merino wool or alpaca wool, but these types of blankets are expensive. I don’t think a survival blanket needs to be bedroom quality. It’s more in the realm of a camping blanket. I think you’ll need to pay around $50 to $60 for the better quality 100% wool blankets.
Pros: wool is naturally fire resistant (but not necessarily so when combined with synthetic fibers). Wool is warmer than cotton. You could always throw a space blanket over a wool blanket for extra warmth.
Cons: A good wool blanket is pricy; cheap ones have problems (smell, falling apart, too thin, not 100% wool). Any wool item can be itchy. A wool blanket is heavy and bulky. Also, you take your chances buying one online.
This material is one of the best synthetic insulations for clothing and blankets. It’s said to be a better insulator than wool by weight, but wool is fairly heavy. So gauging the effectiveness by weight is different than by thickness. And some fleece blankets are all too thin. Polar fleece is relatively inexpensive. A good wool blanket costs more than polar fleece; a lousy wool blanket costs less.
At the high end of the price spectrum for survival blankets is the Mambe “extreme” and “super extreme” fleece blankets. They are waterproof and windproof. They include a reflective lining, that works much the way that a space blanket does, but there is also a fleece layer for added warmth. The “super extreme” version has a reflective layer, a Primaloft layer, and a Polartec fleece layer.
Pros: Fleece is less expensive than a quality wool blanket, and warmer by weight. Quality fleece blankets are easy to find in stores and online. Quality wool blankets are harder to find.
Cons: The highest quality fleece extreme weather blankets are expensive. Fleece is not fire or flame resistant, like wool.
Survival blankets are useful at home, if the power goes out. They work during a bug-out situation, in the car or even camping somewhere. And they are good for emergencies, to keep an ill or injured person warm. I suggest getting at least one of the aluminized tarp versions, and then either a good quality wool blanket or the thickest fleece blanket you can find.