Freezing



Freezing is a game-mechanic which makes surviving Winter more difficult. Whenever a character is away from a heat source for too long they will begin to freeze.

Once the edges of the screen become encrusted with ice (body temperature < 5 degrees), this is a warning that the character is close to freezing, and the player should seek a heat source as soon as possible. When a second layer of ice crust forms over the edges (body temperature < 0 degrees), the character starts to take 1.25 damage each second. Freezing stops soon after the player finds a sufficient heat source.

Freezing can be negated by being near a sufficiently warm heat source, slowed by wearing warm Clothes, growing a Beard or stopped for a limited time by carrying a charged Heat Stone or equipping a Torch.

Fire
The best way to have a reliable and steady source of fire is by having a Campfire or a Fire Pit. A Torch won't provide much warmth but can buy a limited time before freezing actually settles in.

In emergencies, objects and even creatures can also be set on fire for an immediate source of warmth. A single flammable item can be dropped on the ground by holding the CTRL key and clicking the LMB. Once on the ground such items can be lit on fire with a Torch, and will provide a small and limited amount of heat. With enough fuel, small fires like this can provide enough warmth to get to a better source of heat. This might be dangerous (or advantageous) however as nearby flammable objects can catch fire as well.

Warm Clothing
One of the best options for traveling away from a fire during winter is to wear some combination of warm clothing. These items increase the amount of time a character can be away from fire before freezing begins. Having several items equipped at the same time provides a cumulative bonus. Sooner or later however, characters will be forced to return to a source of warmth, wearing insulation merely delays the time it takes before the character starts freezing.

Other options
Although Fire and warm Clothing are the best options for surviving winter, more options exist:
 * Heat Stones can be crafted to carry the heat.
 * Wilson's Beard provides additional insulation depending on its length.
 * Willow's fire will generate a small amount of heat, though it is only available when her sanity is low (and very random).
 * Willow's Lighter produces a very small amount of heat by itself, but in a pinch could be used to light surroundings on fire for emergency heat.

Game Mechanics
Freezing mechanic is based on the temperature implementation in the game. A player character has a body temperature, which ranges from -20 to 40 degrees. Any time the body temperature falls below 0 degrees, the character will take 1.25 damage per second.

Ambient temperature is a key factor influencing a character's body temperature. Body temperature will attempt  to match the ambient temperature, this rate is called the ambient delta.

The speed at which a body temperature decreases to match ambient temperature is any value between 0 and -1 degrees per second given by the function:

max(ambient delta, -30 / (30 + total insulation))

Total insulation is a sum of all insulation currently being worn (see table below).

Ambient delta is the total of the effect of all heat sources affecting the player (including the weather, hot objects in the world such as campfires, and hot objects carried in inventory or equipped, such as heat stones and lit torches).

The effect of a heat source is the difference between the heat generated by the heat source (adjusted for distance for objects not equipped or in inventory) and the player's body temperature. Only heat sources that have an effective heat that is greater than the player's current body temperature will factor into the delta calculation - all others have no effect (unless they are a "cooler", such as the cooling amulet).

The starting point for the ambient delta is the current air temperature, as determined by the weather. Environmental heat sources and carried/equipped heat sources, if hotter than the player's current body temperature, are then each added to the delta.

For each heat source, the player's body temperature is first subtracted from the heat source's heat value, and then added to the delta. Heat sources below the player's body temperature do not affect ambient temperature. For environmental heat sources (e.g. fireplace), the heat from a heat source is less the farther away it is from the player. Carried or equipped heat sources always provide the amount of heat they currently produce (if this is greater than the player's body temperature).

Insulation only becomes a factor if the ambient delta is less than zero (i.e. all ambient heat carried and in the environment is still colder than the player's body temperature), in which case it operates as per the formula above. Insulation provides exponentially less and less protection from cold, so the first item worn makes the biggest difference by far.

If the ambient delta is greater than zero (i.e. the environment is warmer than the player's current body temperature), then the maximum increase of the player's body temperature will be +5 degrees per second while the player's body temperature is below the freezing point (0 degrees), and +1 per second once the player's body temperature is warmer than the freezing point. Note that the increase of the player's body temperature cannot exceed the delta, so the actual rate may be smaller than +5 or +1.

The warmest combination is the Puffy Vest, Beefalo Hat and a fully grown beard (if you are Wilson). This will add up to a whopping 615 points of insulation. With a fully charged Heat Stone and a torch equipped you can have a mobile heat source almost as hot as a stage 1 Campfire.

For the purpose of calculating a Heat Stone's own temperature loss a fixed insulation of 120 is used. This value is NOT added to the player's total insulation, nor does the player's insulation affect the heat stone in any way. A Heat Stone cools at the same rate on the ground as it does in the inventory.

For full list of burnable objects see Fire.

Trivia

 * Sanity, Hunger, and Health do not affect Freezing.
 * With Wilsons beard fully grown, a fully charged heat stone, Beefalo hat, and Puffy vest, you'd last roughly 16.67 minutes in real time without a heat source.
 * Heat Stones only work while their temperature is greater than the player's body temperature; once the Heat Stone cools to below that level, it has no further effect on the player's body temperature.