A heatproof mat is a piece of apparatus

Apparatus

Apparatus may refer to:*Technical term for body of the Soviet and post-Soviet governments *Machine*Equipment*Critical apparatus, the critical and primary source material that accompanies an edition of a text-See also:*Fire apparatus...

 commonly used in tabletop lab experiments that involve moderate temperatures (for example, when a Bunsen burner

Bunsen burner

A Bunsen burner, named after Robert Bunsen, is a common piece of laboratory equipment that produces a single open gas flame, which is used for heating, sterilization, and combustion.- Operation:...

 is being used) to prevent damage to a work surface. They may also be used for domestic equipment, such as hair straighteners, hair dryers or other hot objects.

Traditionally, such mats were made of asbestos

Asbestos

Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...

, often reinforced with a metal mesh, but fiberglass

Fiberglass

Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...

 or other substitutes are now used because of the toxicity of asbestos fibres.