Warming Up is one of the Afflictions that the player can obtain in The Long Dark.
Obtaining
Warming up is obtained when the player consumes a food or drink that has been warmed up over a fire. This includes Coffee, Herbal Tea, Rose Hip Tea, Reishi Tea, Tomato Soup, Pinnacle Peaches, or Pork and Beans. The item must be consumed hot to gain the effect. The teas may be consumed at full Hunger, but everything else will require the player to have lost some calories before eating. However, the player need not eat the full item to gain the bonus.
Other cooked foods, like meat or fish, will not provide this effect.
Effect
The Warming up condition makes the player's Cold meter decrease at a significantly slower rate. While extreme temperatures will still reduce faster, it will not reduce as fast as they would without this condition. Warming up has no effect if the temperature is higher enough to prevent the cold meter from dropping.
Eating any hot food will also provide a straight increase in the player's cold meter, although this is not affected by the warming up condition.