Temperature
The outdoor temperature changes with seasons and the day/night cycle. A room's indoor temperature will slowly drift to match the temperature outside, unless you use heaters or coolers to control it.
Sources
Temperature sources will heat or cool nearby units, even when not placed inside a room. Fire / Campfire: Provide heat. Hydrorock: Uses water to cool the area down to 26°C. Frostrock: Cools to a user-set temperature. Heatrock: Heats to a user-set temperature.
Heatstroke
Caused by exposure to extreme heat. Increases damage taken, reduces healing received and is fatal at 100% severity.
Hypothermia
Caused by exposure to extreme cold. Reduces movement speed and is fatal at 100% severity.
Tip
If a room stays too hot or cold, check enclosure, insulation, room size and the source's target temperature. Supply water, fuel or mana as required by the device and check whether it is enabled. Inspect the unit's temperature and equipment; a nearby source does not guarantee safe conditions everywhere.