How Does an Emergency Blanket Work?

Emergency blankets, often called space or Mylar blankets, are vital tools used by emergency responders and search and rescue teams. You've probably seen them as the shiny, silver blankets wrapped around people after a rescue. They reflect up to 90% of a person's radiated body heat. This helps keep them warm and prevents hypothermia. But how do they work? In this guide, we'll break down the science behind emergency space blankets.

What are Emergency Blankets?


emergency usa emergency blankets


An emergency blanket is a thin sheet made from a plastic material called polyethylene terephthalate (PET) and coated with a thin layer of metal, usually aluminum foil. This metal coating gives them that distinctive shiny look.

NASA first developed these blankets in 1964 for the U.S. space program. They were designed to protect equipment and astronauts so they don't lose heat. Over time, people realized they could be useful for other uses as well.

Today, paramedics, firefighters, and search and rescue teams use them to prevent heat loss in people exposed to cold conditions. They're also commonly found in first aid kits, survival kits, and emergency bivy sack supplies to prevent heat transfer.

How Do They Work?

The human body generates heat naturally. When you're outdoors, you can lose this heat to the surroundings. Emergency blankets work by trapping and reflecting 90% of the heat back to you. They also reflect back any external heat sources to keep you warm.

Besides keeping you warm, they're also designed to be windproof and waterproof. This means they can protect you from cold wind and rain, which can cause you to quickly lose body heat.

How to Use Your Emergency Blanket


A woman wrapping an insulated emergency blanket around herself


Take the space blanket out of its packaging and unfold it completely. Make sure the shiny side faces inward, toward your body. Wrap the blanket around yourself and cover as much of your body as possible, especially your head and neck. If there's extra material, tuck it in to prevent wind from getting inside, or if you have tape or a clip, use it to secure the blanket in place.

Besides wrapping yourself, you can also use these blankets in other ways. You can use it to line the inside of a shelter, reflect heat from a fire, or you can use its shiny surface to signal for help.

How Effective Are Emergency Blankets?

They're incredibly effective but they shouldn't be relied on completely to protect yourself from extremely cold temperatures. They work best when you pair them with other warming gear, like insulating clothing.

Note: These blankets should not be used for extended periods since they are not breathable and can cause moisture buildup from sweat, which may cause you to feel colder over time. They are most suitable for short-term use.

How Much Do These Blankets Cost?


woman and man wrapping an insulated blanket around woman in a stretcher
Credit: Envato Elements/ halfpoint

On average, a single emergency blanket costs between $1 and $5. You can find them at most outdoor stores, online retailers, and first aid kits.

Can You Sleep With an Emergency Blanket?

Yes, you can. Wrap it around yourself with the shiny side facing inward to trap your body heat. Keep in mind that they are not very comfortable and can be noisy. They are best for short-term use in emergencies. For longer periods, a proper sleeping bag or blanket is better.

Types of Space Blankets


police men wrapping an insulated blanket around injured person
Credit: Envato Elements/ Lazy_Bear


There are several types of space blankets. Here are the main types:

1) Standard Space Blankets

These are the most common type. They're made from a thin layer of Mylar coated with aluminum. They're lightweight, compact, and designed for single use. They're also affordable and often included in first aid kits and emergency supplies.

2) Heavy-Duty Space Blankets

These blankets are thicker and more durable than standard ones. They're designed to withstand rougher conditions and can be reused multiple times. They also provide better insulation and are less likely to tear.

3) All-Weather Blankets

These blankets usually have a Mylar side and a more durable fabric side, such as nylon. This makes them more comfortable and less noisy than standard space blankets. They can be used as ground covers, shelter linings, or even makeshift tarps.

4) Two-Sided Space Blankets

These blankets have a different color on each side. Typically, one side is silver to prevent thermal energy loss, while the other side might be a bright color like orange for increased visibility.

5) Insulated Space Blankets

These blankets have an additional layer of insulation, such as foam, between the Mylar layers. They provide extra warmth and are suitable for colder environments but tend to be bulkier.


Are emergency blankets reusable?

Yes, but mostly only heavy-duty types. Standard space blankets are usually designed for one-time use and may tear if reused.

Can I cut an emergency blanket to size?

Yes. Just be aware that cutting the blanket may make it more prone to tearing.

How should emergency blankets be stored?

Store these blankets in a cool, dry place away from direct sunlight and moisture. Consider keeping them in a sealed container.


Emergency blankets are essential tools for retaining body heat in emergency situations. Developed by NASA, they can reflect up to 90% of your body heat back to you. They are windproof, waterproof, and versatile.

Are you looking for the perfect emergency blanket to stay safe and warm? Check out Emergency USA's Emergency Blankets. Our blankets are lightweight, durable, and designed to reflect up to 90% of your body heat, keeping you warm in any situation. Perfect for your first aid kit, car, or backpack. Shop with us today.