EMTs Get a New Way to Treat Heat Victims: Body-Sized Ice Cocoons | In overheated Phoenix, firefighters are carrying giant plastic, ice-filled bags to quickly cool people

But cold water immersion can bring down body temperatures eight times faster, with little risk of triggering other issues, particularly if body temperature is monitored closely with a rectal thermometer, said Douglas Casa, who studies heat-related illnesses and is the chief executive of the Korey Stringer Institute at the University of Connecticut.