When you first start looking for this particular item, you will notice that there are dozens of options out there. You can spend anywhere from $2 to $15 on a single blanket. There are also packs where you can get a dozen or more. Let us look at the differences.
The most common type of emergency blanket is Mylar. This is a thin synthetic material that is generally waterproof and reflective on at least one side. The more expensive blankets are typically a thicker fibrous material designed to be warmer than wool. They are generally a bit larger, have grommets in the corners, and are still waterproof and reflective on one side. Mylar is thin and easy to tear or puncture. The thicker blankets are impossible to tear, tough to puncture, and are even somewhat resistant to melting. I know… I have tried.
So which option is right for you? It really comes down to cost. If you are only buying a few, I would definitely suggest the thicker version. As we go through the uses, it will begin to appear obvious why I feel this way. However, if you are in a situation where you may need to keep a whole group of people warm then a package of the Mylar blankets may make more sense. In an emergency, keeping everybody warm and safe is always your first priority. If you have a family of seven, look at your budget and make sure you have seven blankets.
The obvious use for an emergency blanket is keeping warm. The primary reason these blankets help is that the reflective surface is designed to reflect up to 90% of your body heat back to you. If stuck on the side of the road this function is quite helpful. It also is designed to break the wind. However, the thicker blankets do a much better job of staying tight with your body and keeping the wind out.
Also, the additional insulation from the thicker blankets makes a huge difference. In my very first survival challenge it was pouring rain and temperatures dropped into the 40s. My shelter was only keeping out some of the rain as the 30 mph winds were blowing it in sideways. My fire was out and I finally broke down at 2am and pulled out my emergency blanket. I was instantly warmer and was even able to get some sleep before the sun came up. Also, keep in mind that a Mylar blanket with a hole in it does not work very well. This is why I suggest the thicker version.
In addition to wrapping your body, you can also use some survival blankets to build a shelter. The tarp style blankets are just large enough that you can drape it over a pole or cord and then tie down the corners with stakes. This makes a great pup style tent for one person. I completed a survival challenge this spring in which it rained non-stop for three days and nights. This included a few downpours with very heavy winds. Combined with a raised bed, my survival blanket was my only shelter. I stayed completely dry the entire time. I was amazed.
Here is a video showing a shelter built with a thicker style emergency blanket:
Rain and cold are not the only elements that can hurt you in the wild. The sun can be just as rough. A survival blanket is great for shade and can normally keep your whole body shaded if hung properly. As an added benefit, putting the shiny side out will reflect heat from the sun away from your shelter. This just adds to the cooling effect.
You can also use your survival blanket to build a super shelter. This design works with a clear plastic tarp to keep your shelter super warm even in sub-zero temperatures. Build a simple lean-to shelter with a decent amount of insulation. You have to make sure that the angle of the roof is 45 degrees. Next hang your emergency blanket inside the roof at the same 45 degree angle with the shiny side down. This will reflect heat back to your body. Build an insulated bed and then drape the whole shelter with the clear plastic tarp. Secure the edges to make sure no cold air can get in. Build a body-length fire just outside the plastic and build a deflector wall on the other side to bounce heat back to you. As the heat enters through the clear plastic it is then trapped inside. I have seen this structure raise the inside temperature by as much as 60 degrees versus the outside temperature. This means that it can be 10 degrees outside and you can be cozy in a 70 degree shelter.
Here is a clip from a popular survival show where Cody Lundin shows us a super shelter. This was actually the first time I had ever heard of this design:
There are a few vertical uses for an emergency blanket. The thicker ones can make a great wind block. If you have steady wind blowing in from one direction, you can use cordage to raise up your blanket and block the wind. You may want to do this to stay warmer or to help you start a fire.
In a desert environment, sand blown against your body can do a lot of damage. It can get in your mouth and eyes and sometimes makes it hard to breathe. A vertical wind block can do the trick. You can also use a vertical emergency blanket for a deflector wall. Once you have a fire built, drive a few poles into the ground. Secure your blanket with the shiny side facing the fire. The heat will bounce off and back towards you and your fire.
Emergency blankets can be used to signal for help. The shiny reflective surface is visible from quite a distance. You can also purchase ones that are hunter orange on the other side. If you use your blanket to build a shelter, this ensures that it can be seen no matter which side you face out. If not using it for anything else, it can be used to actively signal. Once you get to high ground, use poles to build a frame. Then stretch the blanket across the frame and secure it with cordage. Once it is fairly flat, you have a good surface to try and signal a helicopter or other vehicle.
If you have no other options, you can sometimes build a fire with your emergency blanket. You have to have direct sunlight and very dry tinder. Use a bowl or other round container and stretch the blanket to line the inside. Smooth out the wrinkles as much as possible. Then take sticks or wire and try to suspend a small bit of tinder a few inches off the bottom of the bowl. You may have to adjust it to find the focal point. If you build it right the sunlight should reflect off the blanket and hit a focal point somewhere in the center of the bowl. In perfect conditions this can get hot enough to create an ember.
Emergency blankets even have a few uses for water. In a tropical climate like the rainforest, most of your water sources are contaminated. However, rainwater can be a clean source of drinking water. You can spread out your blanket with a lip at the base to direct water into a container. You can also build a rain catch with the blanket. Just dig a hole a few inches deep and about a foot smaller than your blanket on each side. Lay your blanket over the hole and use poles or rocks to secure it in place. Make sure that the edges of the blanket come up over the lip of the hole and are secured in place. You have to be cautious that the weight of the water does not pull an edge loose and drain all your clean water.
You can also use your blanket as a container in a few ways. If you have any food that you need to store overnight or while you are away from camp, it needs to be in a bear bag. Place all your food in the center of the blanket. Pull up the edges and bundle the remaining material at the top. Tie it with cordage and throw one end over a branch at least 10 feet off the ground. Then hoist it up and tie off the cordage. If you are worried about squirrels chewing through the blanket, you can put your food in a pot with a lid before you wrap it.
You can also carry water with your blanket. Dig a hole that is about a foot wide and as deep as you can get it. Place your blanket over the hole and then push down at the center point. Try to smooth out the blanket at the bottom to get as much surface area as you can. Make sure there is plenty of blanket still sticking out of the hole all the way around the edges. Pour in your water and stop about six inches from the top of the hole. Pull the edges together, twist them tight, and tie with cordage. You will need to carry the water with the tied end facing up.
There are even a few ways an emergency blanket can help you with food. When fishing, you often need a float to either determine when the fish strikes or mark where you have sunken a trap. It may take a few tries, but you can build a float with your blanket. Form a pocket in the center and then bring your blanket down on the surface of the water evenly. You have to ensure that all edges of your blanket hit the water at the same time so air does not escape. As you push down with your arms, pull the blanket around the bottom of your air bubble. Bring your hands together to close it up, and then tie it off with cordage. This will work best if you keep the opening under water while using it for a float.
An emergency blanket is great to build a smoker for preserving fish or meat. Build a fire and let it burn down to coals. Next you need to build a tripod at least five feet tall. Cut up your meat into strips ¼” thick or less. Check your cooking height with your hand. Hold your hand face down over the coals a few feet off the ground. The correct height will be when you can keep your hand over the coals for eight seconds before pulling it away. Now suspend your meat at that height. You can skewer it on sticks, build a rack, or string it up on cordage.
As your final step, wrap your tripod with your blanket and keep the shiny side facing in. This will hold in the heat and smoke. Make sure you do not let the edges of the blanket get too close to the flames as it could melt. It will take at least eight hours, but your food is preserved once it is dry and firm.
Please see this video for more detail on using your blanket to smoke meat:
As mentioned before, the biggest defect with the inexpensive Mylar blankets is their tendency to tear. However, there are a few things you can do to get the most possible use out of these blankets. Most do not come with grommets in the corners for building a shelter. Find small round pebbles. Place one about an inch from the corner and wrap the blanket around it, then tie cordage around the rock and tie the other end to a stake to secure the corner.
When using your Mylar blanket with sticks for signaling, shelters, a fire deflector, or any other use, you must use caution. Be sure to trim your sticks smooth and try to use ones with smooth bark. If using insulation materials, opt for something fluffy like leaves or dry grass. If your blanket must come in contact with the end of a stick, protect it as much as you can. Carve the end of the stick to be round and smooth and tear off a little piece of cloth to place as a barrier between the two. Remember that a little whole can turn into a huge tear very quickly.
Here is a video showing proper uses of a Mylar blanket:
As you can see, emergency blankets are one of the most practical and underrated objects for survival. They positively impact your efforts for food, water, fire, shelter, and signaling for rescue. Very few other objects are so useful and important for your bug out bag. With the weather conditions I faced, my blanket may very well have saved my life on my first survival challenge. If you are wet, any temperatures below 60 degrees can mean hypothermia and death. For this reason alone, I carry mine with me every time I head into the woods. I suggest you do the same.