Insider asked two scientists for simple, effective, and cheap ways to cool down. Put your hands or feet in cold waterIn extreme heat, the body opens up the blood vessels that are close to the skin. Blood carries heat from inside the body to the surface, where it can benefit from the cooling effect of sweat evaporating. Use an electric fan, but be careful in very hot weatherA fan helps cool you down by helping sweat evaporate faster. In dry heat, sweat is already evaporating at maximum efficiency.

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Persons: George Havenith, Serge Haouzi, Owen Jeffries, Jeffries, Havenith, Coke, Ricardo Rubio, you've Organizations: Service, Oceanic, Atmospheric Administration, Environmental, Loughborough University, Getty, Newcastle University, World Health Organization, China News Service, Europa Press Locations: Pacific, Asia, Nice, France, Xinhua, Chongqing, China, Madrid, Spain