Australian scientists have developed a hi-tech vest that works like a fridge.
It is designed to keep soldiers and emergency workers cool while working in searing heat.
The Commonwealth Scientific and Industry Research Organisation (CSIRO) said the vest is designed to be worn underneath nuclear, biological and chemical clothing or other protective uniforms - which prevent the body from cooling through perspiration.
The lightweight vest, which looks like a flak jacket, allows its wearer to work up to four times longer in temperatures above 35C.
Dr Pratish Bandopadhayay, of the CSIRO's Thermal and Fluids Engineering division, said the vest collects body heat through vapour-filled cavities.
The heat is then transferred via a pipe to the atmosphere with the help of an evaporative cooling heat exchanger.
"In a way, it's like a refrigerator, but it's actually using the body's heat to vaporise and as it does, it cools," Dr Bandopadhayay said.
The vest, which was designed with the help of Australia's Defence Science and Technology Organisation (DSTO), is expected to be used by the military serving in harsh environments, firefighters, miners and those involved in cleaning up hazardous chemical spills.