Space blanket: Difference between revisions
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==Usage== |
==Usage== |
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In their principal usage, space blankets are included in many emergency, [[first aid kit|first aid]], and survival kits because they are usually waterproof and windproof. That, along with their light weight and ability to pack into a small space, has made them popular among outdoor enthusiasts and emergency workers. Space blankets are often given to marathoners at the end of races. The material may be used in conjunction with |
In their principal usage, space blankets are included in many emergency, [[first aid kit|first aid]], and survival kits because they are usually waterproof and windproof. That, along with their light weight and ability to pack into a small space, has made them popular among outdoor enthusiasts and emergency workers. Space blankets are often given to marathoners at the end of races. The material may be used in conjunction with conductive insulation material and may be formed into a bag for use as a [[bivouac sack]] ([[survival bag]]). |
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In [[first aid]] the blankets are used to prevent/counter [[hypothermia]]. A threefold action facilitates this. |
In [[first aid]] the blankets are used to prevent/counter [[hypothermia]]. A threefold action facilitates this. |
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Revision as of 21:21, 20 October 2009
A space blanket, also known as a mylar blanket, first aid blanket, emergency blanket or weather blanket) is a blanket used in emergency situations to reduce heat losses in a person's body due to thermal radiation and convection.
Manufacturing
First developed by NASA in 1964 for the US space program[1], the material consists of a thin sheet of plastic (often PET film) that is coated with a metallic reflecting agent, making it metallized polyethylene terephthalate or MPET, usually gold or silver in color, which reflects up to 97% of radiated heat.[2][3]
In the US, space blankets are made by vacuum depositing a very precise amount of pure aluminum vapor onto a very thin, durable film substrate.
Usage
In their principal usage, space blankets are included in many emergency, first aid, and survival kits because they are usually waterproof and windproof. That, along with their light weight and ability to pack into a small space, has made them popular among outdoor enthusiasts and emergency workers. Space blankets are often given to marathoners at the end of races. The material may be used in conjunction with conductive insulation material and may be formed into a bag for use as a bivouac sack (survival bag).
In first aid the blankets are used to prevent/counter hypothermia. A threefold action facilitates this.
- The airtight foil reduces convection
- Heat loss due to evaporation of perspiration, moisture or blood is minimized by the same mechanism
- To a limited extent the reflective surface inhibits losses due to thermal radiation. This is why it's more effective to use the silver side towards the body, if the blanket has two differently colored sides.
In a hot environment they can be used to provide shade, but using them to wrap a person would be counterproductive, because body heat would get trapped by the airtight foil. This effect would exceed any benefit gained from heat reflection to the outside.
Space blankets are used to reduce heat loss from a person's body, but as they are constructed of PET film, they can be used for other applications for which this material is useful, such as insulating containers, for DIY solar projects, and other applications.
See also
- Aluminize
- Bivouac sack (bivy sack)
- Body heat
- Emissivity
- Thermal insulation
- Radiant barrier
- Reflectivity
- R-value
- Survival bag
- Wilderness first aid