What fabric(s) can contain/spread heat?

[KrisEE]

I am curious what kind of fabrics (be specific) are used in products such as heated blankets which shield the heated wires, and are resistant to the heat, preventing it from burning. I imagine the wires are simply stitched inside this material and the whole blanket isn't made up of the fire-resistant material.

Sorry if I am being a bit vague here, but I assume this is a pretty to-the-point question.

 

[PietKuip]

Refrasil is a name that comes to mind.

(But not for blankets to sleep under, I think. Lint from this material is rather irritating between fingers...)

 

[CWatters]

Electric blankets of the type used to heat a bed don't get very hot. This site has some construction details but says the wires are insulated with a "proprietary plastic" and then a polyester and acrylic fabric.

http://www.madehow.com/Volume-6/Electric-Blanket.html