rewarm

Rewarm is the act of warming something that has cooled, or raising its temperature again after cooling. The term is formed from the prefix re- (again) and warm.

In medicine and clinical care, rewarming is used to treat hypothermia and to restore body temperature after procedures or accidental exposure. Methods include passive external rewarming (insulating blankets or clothing), active external rewarming with devices such as forced-air warming blankets, and active internal rewarming using warmed intravenous fluids, warmed humidified gases, or warmed irrigation solutions. The approach depends on the severity of hypothermia and patient risk. Potential complications include rewarming shock and electrolyte or acid-base disturbances, so monitoring is important and gradual temperature restoration is often pursued.

In food service and household contexts, rewarming refers to heating previously cooked leftovers or meals to serving temperature. Food safety guidelines emphasize reaching an adequate internal temperature to destroy pathogens (commonly around 74°C or 165°F for many foods) and avoiding reheating multiple times. Quality issues can arise from improper rewarming, such as uneven heating or texture changes.

In engineering and cryogenics, rewarming describes returning a system from a cooled state to its operating temperature. The rate of rewarming is important; too rapid a rate can cause thermal stress, ice formation, or material damage. Specialized equipment and controlled heating are used to achieve uniform and safe warming.

See also: reheating, warming, hypothermia, cryopreservation.