When venturing out into the wilderness, it’s always good to be prepared for any type of emergency survival situation. As such, adding an emergency blanket to your kit can seem like a really good idea as they’re supposed to help you stay warm in cold environments. But, do emergency blankets actually work and is it worth it to add one more thing to your pack?
The effectiveness of emergency blankets will vary based on the situation but can work for helping you retain body heat for longer periods of time through solar heating. However, emergency space blankets don’t work well at night or when the sun isn’t present. Even so, they can enhance the effectiveness of other insulated gear.
In addition, emergency blankets can also be utilized in many other ways that are useful in a survival situation. Keep reading to find out more about emergency blankets, the best ways to use them, and what they aren’t useful for!
What Is An Emergency Blanket Good For?
As you may already know, an emergency blanket (AKA space blanket) is a sheet of metalized plastic similar to aluminum foil. Originally created by NASA in the 1960s, emergency blankets were first designed to be sun shields for space stations. Over time, they began to be repurposed for other uses such as emergency blankets for survivors of natural disasters and, more recently, for outdoor enthusiasts and people that find themselves stuck in survival situations.
The effectiveness of an emergency blanket will vary based on the type of situation you’re in. In general, modern emergency blankets are primarily designed to help people retain body heat to keep someone from freezing to death in extreme conditions. Throughout a day, people lose body heat through three natural processes: radiation, convection, and conduction.
- Radiation is the loss of body heat when it emanates from your body and dissipates in the environment
- Convection is the loss of body heat from contact with outside forces such as wind and cold
- Conduction is the loss of body heat by transfer to other objects.
An emergency blanket helps you keep much of the body heat that you would lose naturally by preventing it from escaping through radiation and convection. They have a double-sided design in which the outside of the blanket can help protect against the loss of body heat through exposure to the elements while the inside of the blanket has thermal-reflective qualities which redirect heat radiating from the body back to the person rather than allowing it to escape.
Despite the fact that it is called an “emergency blanket”, this items ability to keep you warm and help you generate new heat is entirely dependent on direct, sustained contact with solar energy. This is because the emergency blanket does not have any insulating properties, so it can’t generate heat on its own. As such, an emergency blanket cannot keep you warm when you’re in the shade or at night.
This is important to know because when you’re in a survival situation involving a cold environment, it’s essential to be able to keep yourself warm at night and in the shade on sunny days.
Along with this, it should be kept in mind that an emergency blanket can’t keep you from losing your body heat altogether. An emergency blanket can help you retain 90% of the body heat that you lose from radiation or convection, but you will still continue to lose about 10% of your body heat consistently.
Ineffective Against Conduction
An emergency blanket cannot keep you from losing body heat through conduction (heat-transfer). This is important to know because the loss of heat through conduction is a natural process that happens in all environments, but is accelerated in cold environments.
This is because the temperature of an environment is also conducted into your body and your clothes as your natural body heat is conducted out. As a result, you will lose more body heat as your body tries to compensate for the surrounding environment, and unless you have some type of heat being conducted into your body to replace what you lose your body temperature will continue to drop.
In fact, in a cold environment, you will eventually lose all of your body heat even with the help of an emergency blanket and become susceptible to freezing. Also keep in mind that they will not work at all if you’re trying to sleep in the snow or directly on damp or frozen, as the blanket will not prevent the cold from conducting into your body and the heat from conducting out.
Survival Blanket Flaws
Along with its inability to generate new heat on its own or help you completely retain your body heat over long periods of time, there are other flaws with an emergency blanket that should be taken into consideration – especially if you intend to rely on it in a survival situation.
They are really fragile
One main concern with an emergency blanket is that they are fragile and are very easily damaged. Emergency blankets are essentially thin sheets of metalized plastic, and they’re designed to be disposable rather than durable. As a result, they are very easy to rip when trekking through the outdoors on obstacles such as branches, bushes, or even sharp rocks.
I’ve known people who have ripped their emergency blankets just from rolling around in their sleep. If an emergency blanket gets even a small hole in it, it will not be able to help you retain your body heat and will become virtually useless.
They are useless if you’re wet
Another thing to keep in mind is that emergency blankets will not help you retain your body heat if you’re wet. Actually, using an emergency blanket while you’re wet will likely prevent you from drying off and can also make you colder.
This is because an emergency blanket is designed to help you stay warm by reflecting the body heat that you radiate back to you rather than allowing it to escape. When you’re wet, you radiate cold air as the water begins to dissipate and your body attempts to dry off. If you were to wear an emergency blanket while wet, it would reflect this cold air back to your body, which would make you colder and prevent you from drying off.
We definitely don’t want that.
They can warm you, but not help dry you off
Bearing in mind that emergency blankets can use solar energy to warm you up, it can seem like a good idea to use it to help you sun dry, right? Sadly…no. In order to utilize solar heat with an emergency blanket, you have to turn it inside out to use its reflective side.
The problem with this is that the outside of most emergency blankets are designed to be water repellent to keep you dry, which means that the blanket will not absorb the water molecules as they start to evaporate from the heat.
If anything, you’ll probably end up creating a lot of condensation what will either stay trapped in the blanket or evaporate through the hole where your head is. Based on that, it’s probably best to stick to direct sunlight if you want to dry off after taking a dip!
So Are Emergency Blankets Useful At All?
Although there are a number of flaws in emergency blankets that should always be taken into consideration, they can still be useful in a survival situation.
They enhance the effectiveness of other tools
Emergency blankets work best when used with other camping gear meant to help protect you from the elements, which can compensate for the weaknesses of an emergency blanket.
One of the best ways to use an emergency blanket is with a sleeping bag. If you wrap up in an emergency blanket before and then bed down in your sleeping bag for the night, it will keep you from losing much of the body heat that you would have without it. As a result, you will stay a lot warmer throughout the night. Correspondingly, your sleeping bag will protect your emergency blanket and keep it from getting damaged. The sleeping bag will also compensate for some of the things that the emergency blanket can’t do, as most sleeping bags have some form of insulation in them and can keep you from losing body heat through conduction as well as protect you from having cold air conducted into your body. This combo is definitely a win-win!
Another way to utilize an emergency blanket to your benefit is to use it with insulated clothing made out of wool, fleece, or polypropylene. Unlike emergency blankets, insulated clothing can keep you warm by generating heat as well as helping you retain your own body heat. In addition, insulated clothing is usually much more durable than an emergency blanket.
When paired with insulated clothing, emergency blankets can enhance this ability to retain your body heat and can provide further protection against exposure to the elements. When you’re in a survival situation, you definitely want to take every benefit you can get.
Emergency Blankets for Survival
If you do get into a survival situation where all you have is an emergency blanket, it’s best to use it either as a solar-heater or as a makeshift sleeping bag.
Most emergency blankets do work for helping you retain body heat and they can warm you up through solar-heating. However, emergency blankets can’t keep you warm in every situation and are relatively fragile when used in an open environment.
Using an emergency blanket when there is sunlight
As we discussed earlier, the only time an emergency blanket can help you generate heat is when it’s using solar heat. As such, if you want to use an emergency blanket to keep you warm then you should utilize its solar-thermal capabilities as much as you can.
To do this, just make sure you’re standing out in direct sunlight and turn your blanket inside-out so that the shiny, reflective side is facing outward. As long as you sit in the sun, the thermal-reflective properties of the blanket will help you keep warm. However, this method will not work in the shade or at night.
Using an emergency blanket when there is no sun
If you do need to use the emergency blanket when you don’t have sunlight, your best bet would be to mummify yourself in the blanket as much as you can. If you’re on the move, try to wrap the blanket around your body as tightly as you can and, preferably, secure it with some kind of rope. The less room between you and the blanket the better.
For nighttime use, turn it into a makeshift sleeping bag by wrapping the blanket around yourself and tucking 3 of the 4 corners under your body so that there is only one opening big enough for your head to stick out. This will maximize the blankets’ ability to help you retain body heat and it will protect you from the cold in the ground to some extent. However, you will need to make sure not to roll around because it will be easy to rip the blanket.
Other Uses for Emergency Space Blankets
Although emergency blankets are limited in their ability to keep you warm in a survival situation, they can be repurposed in a number of ways that can be useful, even necessary, when you’re out in the wilderness.
One way in which an emergency blanket can be repurposed is as extended protection from the elements, such as a windbreaker or a canopy. To use the emergency blanket in this way, just turn the outside of the blanket away from you and then set it up vertically to act as a windbreaker, or fasten it to something over your head to act as a canopy.
Because the blanket was designed to be exposed to the elements, it should work well in keeping you from being exposed to them as well. Similarly, an emergency blanket can also be used as a rain poncho thanks to its water repellent properties. Just cut a hole in the blanket big enough for your head to get through.
Another way you can repurpose an emergency blanket is for medical purposes such as a tourniquet or a sling. Although the material of an emergency blanket isn’t very durable, it is flexible enough to be contorted into all sorts of shapes.
- To use the emergency blanket as a tourniquet, just tear off strips of the blanket and tie them where you need them.
- Similarly, you can also turn your emergency blanket into a make-shift sling by cutting a hole into the side of the blanket large enough for your head, placing your arm in the blanket, and tying the two corners around the back of your neck. So if you break something while trekking through the wilderness, an emergency blanket could help you make it back to camp.
Emergency blankets can also be used for starting fires by concentrating the reflection of the sun onto a piece of tinder, or as signals by contorting the blanket so that the reflection of the sun on the blanket flashes. Along with that, an emergency blanket can be useful for helping you keep things dry that you don’t want to get wet, such as food, gear, and firewood. As such, an emergency blanket could be a good addition to a survival kit for a number of reasons, even if it isn’t the best tool for keeping you warm
Other Gear Keep to Keep You Warm
If you want to keep yourself warm in a survival situation, there’s really no one piece of gear or method to make sure that you stay nice and toasty no matter the weather.
Rather, it’s better to rely on multiple types of gear and ad-hoc tricks to make sure you stay warm, that way you can use them in many different situations. Fortunately, there are different types of camping gear and easy tricks that can help you stay warm no matter how cold it gets.
When in a survival situation, your ability to stay warm will depend a lot on your gear.
- As I mentioned earlier, insulated clothing and a good-quality sleeping bag are some of the best options to keep you warm. Not only will they help you retain your existing body heat and generate new heat, but they will also keep you from sleeping directly on the ground which is something you want to avoid at all costs if you want to stay warm.
- Insulated sleeping pads are also good investments if you intend to venture out into cold environments. Insulated pads, such as Ensolite Pads, are made with closed-cell foam that is specifically designed to help retain heat in cold environments.
- Similarly, insulated tents are made with types of fiber and polyurethane designed to keep the heat in and the cold out.
- Sometimes, even a simple wool blanket can mean the difference between a cozy night’s sleep and spending the whole night shivering. Wool and fleece are some of the warmest materials to make cloth out of, and you can normally choose whether to buy a heavy wool blanket or a light one. Not only will these blankets help you keep the cold out when you sleep under them, but you can also sleep on top of them to protect yourself from the cold ground.
Hacks For Staying Warm
Unlike Halloween, when it comes to staying warm outdoors your tricks are your treats.
- Improvised Made Heating Pad – One great way to keep yourself warm is to make an ad-hoc heating pad using a hot water bottle. To use a heated water bottle, just heat up some water and pour it into a metal container. After that, put it close to your body in between layers of clothing. You don’t want it to close too your skin or it could burn, but you don’t want it to have it on the outside of all your clothing or the heat won’t reach your body.
- Use Heated Rocks – If you don’t have a metal container, you can actually heat rocks and put them in between layers of clothing as well. The rocks will retain heat for a long time, but you want to be careful not to heat them for too long or they will break.
- Use Natural Insulation – Another way to keep yourself warm is to acquire some type of insulation. Wood, hay, and paper are the best materials to make insulation out of but dry leaves will do in a pinch. Just make sure that whatever you use is completely dry and you put it closest to the parts of your body that lose the most heat, such as your torso, feet, and the top of your head. Make sure to pack it tightly under your clothing so it won’t shift and fall out. The insulation will prevent the rapid loss of body heat in those areas and will let some of that heat transfer back into your body. If you have insulation while you’re on the move, it will help you generate more body heat as you travel.
What I like about emergency blankets is that they are really light and easy to carry. So taking them with you won’t be that much of a hassle at all. In my opinion, their portability and versatility make them essential for any survival pack.
Do space blankets keep things cold? A space blanket has poor insulating properties and is not great at keeping things cold. However, it could be placed over a cooler to act as a reflector to the sun and outside heat.
Do emergency blankets expire? Emergency blankets do not expire, they are made from materials with an indefinite shelf life.
Can you reuse emergency blankets? Emergency blankets can be over and over until they are damaged. Once the material has a hole, the blanket will become much less effective.
Attributions: Main photo- Paul Holloway from Birmingham, United Kingdom [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)]
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