London:
Scientists have developed camouflage 'make-up' that not only helps soldiers hide from the enemy, but also shields them from the searing heat of bomb blasts.
The heat-resistant face paint, developed for the US military, has been described as one of the most fundamental changes in thousands of years to camouflage, the Daily Mail reported.
Researchers from the University of Southern Mississippi developed a material from silicone powerful enough to protect against a thermal blast that can reach 600 degrees Celsius (1,112 degrees Fahrenheit), as hot as a burning cigarette.
"The thermal blast lasts only two seconds, but it can literally cook the face, hands and other exposed skin," lead scientist Dr Robert Lochhead, said.
Lochhead and colleagues set out to find a material that soldiers could smear on their faces like suntan lotion yet protects against heat far hotter than the rays that normally reach the skin.
The formulation they discovered lasts far longer than a normal two second blast, generally providing protection for up to 15 seconds and 60 seconds in some tests before its own temperature rises to the point where a mild burn could occur.
The finding raises the possibility that other professions exposed to intense heat, such as fire fighters, could also use a colourless version.
The task was difficult as traditional makeup ingredients oil or wax-based face paint could not be used as it can melt on the face and burn the skin when in contact with intense heat.
So instead they turned to non-flammable silicone. The makeup also had to be waterproof and non-irritating, and, in an extra challenge set by military rules, contain the insect repellent Deet.
"Deet also is flammable, so when the Department of Defence asked us to incorporate it, we didn't think we could do it," Lochhead was quoted by the paper as saying.
Their solution was to encapsulate the Deet in a water-rich material that prevented it from catching fire. The study was presented at the annual meeting of the American Chemical Society.