Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A mylar blanket is a thin, shiny, metallised plastic sheet sold as an emergency blanket or space blanket. Its job is to hold back radiated body heat, which is why it turns up in first-aid kits, race-finish areas and disaster-relief supplies. This guide draws on NASA, the original developer of the technology, and the UK National Health Service (NHS), and it keeps product claims apart from general facts.
What is a mylar blanket?
A mylar blanket is the everyday name for an emergency blanket, also called a space blanket: a lightweight, highly reflective insulating sheet. NASA’s technology-transfer history says these “so-called space blankets, also known as emergency blankets” were first developed by NASA in 1964 and describes them as highly reflective insulators that are often included in emergency kits.
Its purpose is simple: reduce heat loss from a person or a space. It is a thermal product, not a dressing or a treatment.
How is a mylar blanket built?
NASA’s 2006 Spinoff report describes the material as a strong, plastic, vacuum-metallized film with a highly efficient, infrared-reflective, vapor-deposited coating of aluminum. Vaporized aluminum is applied to a very thin plastic sheet, which gives a material that stays flexible while reflecting infrared (radiant) heat.
That construction explains the mechanism. The blanket works by reflecting heat rather than by trapping air the way a wool or fleece blanket does. Be careful with percentage claims: the same NASA report quotes “up to 90 percent of a person’s body heat” reflected, but it attaches that figure to one named commercial product, an emergency sleeping bag from Adventure Medical Kits. Treat it as that product’s claim, not a rule for every blanket.
Who uses a mylar blanket?
Users range from space agencies to clinics and event organisers:
- Spaceflight programmes. NASA reports the reflective film is used on virtually all of its manned and unmanned missions, including the base of the Apollo lunar lander.
- Race organisers and runners. NASA notes runners use the blankets to avoid a large swing in body temperature after a race. The 2006 report says marathon finish-line blankets are mostly used for the purposes of preventing hypothermia.
- Disaster relief. The same report describes earthquake relief blankets sent to Pakistan.
- Outdoor and emergency kits. NASA says the material is incorporated into outdoor clothing and sleeping bags, and emergency blankets are often included in emergency kits.
Types and variants
The sources describe the same reflective film in different formats. This table lists only what they state.
| Format | Typical use (as stated by the source) | Source |
|---|---|---|
| Emergency (space) blanket | Highly reflective insulator, often included in emergency kits | NASA, Emergency Blankets |
| Race finish-line blanket | Helps runners avoid a large swing in body temperature after a race; mostly used to prevent hypothermia | NASA, Emergency Blankets; NASA Spinoff 2006 |
| Emergency sleeping bag | Hiking and camping gear; the “up to 90 percent” figure is one named product’s claim | NASA Spinoff 2006 |
| Relief blanket | Used in earthquake relief, for example in Pakistan | NASA Spinoff 2006 |
| Reflective film in clothing and sleeping bags | Incorporated into outdoor clothing and sleeping bags | NASA, Emergency Blankets |
How to use a mylar blanket
A mylar blanket is only one step in caring for someone who is cold. For suspected hypothermia, the NHS advises moving the person indoors or somewhere sheltered as quickly as possible, removing any wet clothing, and wrapping them in a blanket, sleeping bag or dry towel, making sure their head is covered. The NHS page names ordinary blankets and does not specifically mention foil blankets, so a mylar blanket is best read as one wrap option in an emergency kit, not as something the NHS endorses by name.
The same NHS guidance says to call 999 or go to accident and emergency if hypothermia is suspected, and not to drive the person yourself. If the person is awake, a warm non-alcoholic drink and sugary food can help. Keep them talking and stay with them until help arrives.
Safe use and handling basics
- Get the person out of the cold or wet first, then wrap them; a blanket on its own does not replace shelter.
- Cover the head as well as the body, as the NHS advises.
- Seek emergency medical help for suspected hypothermia rather than relying on a blanket.
- Keep supplies with your other kit items. See OSHA-compliant first aid kit stocking and stocking an emergency trauma response kit for how kits are planned.
Common mistakes
The NHS lists what not to do when someone may have hypothermia. These apply whether or not a foil blanket is in use:
- Do not use hot baths, hot water bottles or heat lamps to warm the person.
- Do not rub their arms and legs.
- Do not give alcohol.
Another common error is assuming a blanket is enough. The NHS advice is to remove wet clothing, get to shelter and call for help.
Where it fits in kit planning
Emergency blankets are one small item in larger supply plans. For example, disaster relief medical supply cache planning and marina and boat first aid kit requirements cover how kit contents are decided, and what is emergency preparedness gives the wider context. For stocking, browse emergency and trauma response supplies.
FAQ
How do I use a mylar blanket?
Get the person out of the cold or wet, remove any wet clothing, and wrap them, covering the head, as NHS hypothermia guidance describes for blankets generally. Then call emergency services if hypothermia is suspected and stay with the person until help arrives.
What is a mylar blanket made of?
NASA describes the material as a strong plastic, vacuum-metallized film with a vapor-deposited aluminum coating that reflects infrared heat.
Who invented the space blanket?
NASA states that space blankets, also known as emergency blankets, were first developed by NASA in 1964.
Does a mylar blanket reflect 90 percent of body heat?
That figure appears in NASA’s 2006 Spinoff report as a claim for one named emergency sleeping bag, so it should not be applied to every blanket.
Sources
- NASA, Emergency Blankets (40 Years of NASA Spinoff), checked 2026-10-29.
- NASA Spinoff 2006, Reflecting on Space Benefits: A Shining Example, checked 2026-10-29.
- NHS, Hypothermia, checked 2026-10-29.
