Extremely cold, sub-zero weather conditions can kill, even after only a short time. Poorly insulated clothing can result in life-threatening respiratory and cardiovascular problems, as well as frostbite and hypothermia.

People survive longer in severe cold if they wear clothing and outerwear that are specially designed for cold-weather conditions. Knowing the amount of a time a person can survive for a set of environmental conditions is critical for developing new fabrics and clothing that extend survival time.

To improve the design of advanced, cold-weather fabrics, researchers at the Department of Mechanical Engineering at the Indian Institute of Technology in New Delhi undertook a series of experiments to evaluate how three key factors—ambient temperature, fabric insulation, and metabolic heat (heat generated by a person as a function of the physical work performed)—impact survival time. Their research is described in a paper published by the Journal of Heat and Mass Transfer in July 2023.