Heating in "Ice Steam Age 2" is a very important thing in the game, because most buildings need to be heated to prevent the people inside from freezing to death. If you want to reduce the heating demand, you can divide various areas into Group together to gain a heating bonus, which reduces the building's heating needs.
How to reduce heating demand in Ice and Steam Age 2
As a city grows, keeping areas together is an essential element in ensuring its survival, especially on higher difficulty settings.
Any area with three tiles in contact with three adjacent tiles will generate 20 points of heat.
This means that you should plan your buildings so that each area receives this bonus at least once, if possible.
This reduces the building's heating requirements.
An area can receive this bonus multiple times, as long as you align it correctly with adjacent areas, but it's not that simple!