Temperature is a game mechanic that controls how warm or cold the player is. It is depicted by a thermometer at the left of the UI. During most gameplay, the character will not have to worry about temperature; however, when venturing into the Cave of Ringing Wind, the temperature will drop to 20. The player will need a Warm Hat. If the temperature drops too low, the player will begin losing Health. When the player is venturing into Sunglade, you will increase temperature to 80. Once it rises above 75, you will start taking 5 damage in certain increments. You can negate this rise using an Ice Necklace.
The default temperature for Willie and Annie is 50; for Fiery, it is 451.