Temperature is an important consideration in colony management. In some biomes temperature can reach extreme highs and lows. Temperature also plays a major role and is affected by many things in world generation. The temperature in the outdoors stay fairly consistent. Temperature can be used as a weapon for any player with adequate power to burn in a raid.
As of Alpha 14 (July 15th, 2016), there is an orange glow when hovering over very hot areas to help you identify them. In these areas, it is so hot that things will spontaneously catch fire.
Temperature affects many aspects of your colonist's life. Cold temperatures will preserve food and freeze your colonists to death, while hot temperatures will rot food, cook colonists, and can even start fires. Temperature is determined by the climate of your biome and is managed through structures in the temperature menu.
All indoor rooms have their own temperature which can be seen by mousing over it. Temperature equalizes through roof and walls, with higher temperature differences and more connecting tiles having a stronger effect. Larger rooms have more "mass" to maintain their temperature and will have more authority over smaller rooms. Unroofed areas will always immediately match the outdoor temperature, even if only one tile is unroofed.
Temperature transfer inside a room is instantaneous regardless of room size. This means long hallways can be used to transfer hot or cold quickly through a large base. Double thick walls act as an insulator to reduce heat transfer between rooms. Any room that borders an outdoors area will try to match the the outdoors temperature, even if the room borders solid rock. Rooms with extreme temperature differences can be buffered with an intermediate room, such as by using a cold hallway to protect a warm bedroom from a frozen outdoors.
Try not to build long thin hallways connecting outside your base, or leave large solid rock clusters inside your base. This will increase your surface area against outdoor temperatures and make it more difficult to manage. Cut off the hallways using doors and mine the rock until all traces of outdoor area are gone.
For the most part your colonists do not require an ideal temperature all the time to be happy. They only become unhappy with sleeping in an overly cold or hot bedroom and only suffer damage if they lack proper clothing for a hot/cold day. A colonist at risk of injury will first suffer unhappy thoughts about their temperature and will attempt to find more suitable clothing to be comfortable.
A freezer is the most straightforward use of coolers for a starting colony. Building one is as simple as making a room and replacing some wall tiles with coolers. Direct the cold "blue" zone of the cooler inside the room and the hot "red" tile to an outdoor area. Select the cooler temperature settings and reduce their target temperature so that they continue running below 32F/0C. As the room cools down any food left inside will decay more slowly until it freezes. Frozen food will stay fresh indefinitely and incurs no other benefit or penalty when eaten.
Building freezers that can tolerate extreme heat, due to biome or heat waves, can be challenging. Materials have the same insulation values in-game so the material used to build the walls does not matter. On the other hand, increasing the thickness of freezer walls from 1-thick to 2-thick dramatically improves the insulation provided, though coolers will not function if their exhaust port is blocked, and increasing thickness beyond 2-thick does not have a noticeable effect.
Freezers lose a great deal of cooling through the doors to the freezer. This loss can be offset by having doors arranged in sequence, one after another, at points of egress, in an "airlock" like fashion. The loss can be examined by mousing over the sections of the airlock to see the temperature. Using doors rather than autodoors can help reduce the cooling lost, though this slows down colonists.
Temperature management is important for any colony, regardless of climate. It can be simply managed with a good power supply and the following structures:
The cooler is primarily used to lower the temperature of a room. It has two states of power consumption: low and high. In its low state, the cooler produces no heat or cold but still requires 20 W. It can be used to lower the temperature of a room to a comfortable 20 degrees Celsius (room temperature) in the summer or create a walk-in freezer for your food. In hot biomes such as desert or rainforest, having comfortable air conditioning is a necessity for any base.
Coolers are heat pumps that produce both a cold side and a hot side. The hot side is rarely useful and should be directed to an outdoor space to not inconvenience your colony.
A cooler (in theory) is able to cool a single square by about 1800 kelvin [K]. But this is not a linear relation as a room always exchanges heat with adjacent rooms and/or the outside. Example: In a realistic setup, this means it can cool a room with 50 squares by an average of about 36 K per square. So a room with 50 squares and an outside temperature of 60 °C / 140 °F can be cooled down to comfortable 24 °C / 75 °F or something near that with a single cooler.
A low-tech cooler useful for tribe starts. A passive cooler cannot cool rooms to a temperature lower than 15 °C and it only lasts 5 days.
The heater is used to raise the temperature of a room. It has two states of power consumption: low and high. In its low state, the heater produces no heat but still requires 10 W. It can be used to raise the temperature of a room to a likable 20 degrees Celsius (room temperature) in the winter or create a walk-in heat trap for your foes. In any cold biome, such as the Tundra, the heater is a necessity for any base.
A heater (in theory) is able to heat a single square by about 1800 kelvin [K]. But this is not a linear relation as a room always exchanges heat with adjacent rooms and/or the outside. This heat conduction effect can be pretty noticable in extremely cold or hot environments. Example: In a realistic setup, this means it can heat a room with 50 squares by an average of about 36 K per square. So a room with 50 squares and an outside temperature of -10 °C / 14 °F can be heated up to comfortable 26 °C / 79 °F or something near that with a single heater.
A campfire heats a room and produces light at level 50% up to five squares away. A campfire can be used to make simple meals, pemmican, or burn drugs and apparel. A cook stove is needed to prepare better meals. A campfire will last for four days - the remaining time is shown in the inspect pane.
Campfires are a quick and dirty solution to produce heat in a hurry. They require no energy, but are temporary structures and must be refreshed with wood every few days. Otherwise they produce the same amount of heat as an electrical heater.
They cannot raise the temperature to over 30 degrees Celsius.
Produces light and a small amount of heat. Must be refueled with wood periodically like campfires.
Steam Geysers generate a constant source of heat and are unaffected by building a Geothermal generator on top of them. They are extremely useful for staying warm in frozen climates but can cook a tightly packed indoors space in warmer biomes.
A vent conducts some of the temperature from one room to another room. It structurally acts like a wall to separate rooms and it supports a roof. Placement of a vent requires open space on its two sides. The blueprint can be laid atop an existing wall; the wall is replaced upon construction. The placement of multiple vents along a wall increases the temperate transference.
Vents work best when connecting directly to a climate controlled room. Trying to chain vents across smaller rooms will lead to each successive room getting less effective climate control, and connecting to a hallway won't work well if the hallway is blocked with doors.
Open doors will cause heat to transfer between rooms. Strangely enough this effect is less potent than using vents, but a door can be left permanently open to help control temperature. Similar to running double thick walls, having double doors will improve insulation between rooms.
Extreme Temperature Effects
As of Alpha 15 (August 28st, 2016), the maximum temperature is 2000 °C and the minimum is -270 °C, very close to absolute zero. The minimum temperature is not encountered during normal unmodded gameplay, but fires in small enclosed spaces can reach the maximum temperature. The gear tab also shows aggregate stats about comfy temperatures.
Temperatures below a pawn's minimum comfortable temperature or above their maximum comfortable temperature will cause them discomfort with mood debuffs and in extreme cases can cause death. The simple cure for any afflicted colonist is to return them to a normal temperature environment. This process can be sped up by forcing the colonist into the opposite extreme, such as putting heatstroke victims in a freezer to cool off.
- Heatstroke - caused by prolonged exposure to heat.
- Burns - caused by exposure to extreme heat or contact with fire.
- Hypothermia - caused by prolonged exposure to cold.
- Frostbite - injury to extremities caused by prolonged exposure to cold.
Objects such as wooden structures and furniture will ignite once they reach a high enough temperature, depending on their material's flammability. All stone types and uranium have their flammability set to 0% and therefore objects made from them will not ignite or burn in any temperature. Steel, plasteel, silver, gold and jade are flammable as materials, but not as items.
Extreme cold has no effect on objects, but most Food and Plant Matter items spoil depending on temperature. They become refrigerated in ambient temperatures below 10 °C, slowing down the spoiling process. When temperature reaches freezing (0 °C), they become frozen and completely stop spoiling.