PneumaticCraft adds a whole heat system. It behaves similar to how heat spreads in real-life. It has some similarities with how pressure disperses too:

-Heat will disperse from hotter objects to colder objects.
-Blocks will only spread heat to adjacent blocks that work with heat.
-The bigger the temperature difference, the faster the spread.
-Different objects have a different thermal resistance. Torches and Air have a high resistance, where machines like a Plastic Mixer have a very low heat resistance. This determines how fast heat can spread from one object to another.
-Different objects have a different thermal capacity. The higher the capacity, the slower the temperature will rise for the given heat. Similarly, the slower the temperature will drop for the given heat loss.

Because of performance reasons blocks like Ice and liquids are static in terms of temperature. You won't ever be able to heat/cool these objects to a point where they will change. Due to this, for balance reasons blocks like Ice and liquids have a high thermal resistance.

Static heat sources are:
-Air
-Ice
-Packed Ice
-Snow
-Torch
-Fire
-Any Liquid (including Water and Lava)

Dynamic heat sources, used to control heat:
-[link{block/vortexTube}]Vortex Tube[link{}]
-[link{block/compressedIronBlock}]Block of Compressed Iron[link{}]
-[link{block/heatSink}]Heat Sink[link{}]