Salicin: World Heat

Heat sources such as lava, fire and campfires emit heat particles, which travel in a direction through blocks and split as they spread. Each block carries a conductivity value, and the heat it holds decays over time. The simulation is built as a light weight engine for world heat radiation, so it tracks thermal energy as discrete particles rather than as fixed temperature values.

Particles stored in chunk data persist when a chunk unloads and are restored on re-entry, which keeps temperature from dropping each time a player returns to an area. Blocks can register their own thermal properties through the SWHRegistrateAPI, a separate API that lets other mods add support without a hard dependency on it. The mod also ships a client renderer that draws heat particles and can be toggled with the enableHeatParticleRender option.

The mod runs on the server and on the client, so both need to install it. Configuration covers 24 server-side and 9 client-side options, several flagged with performance warnings. Files exist for Forge only, on the 1.20.1 game version, in the alpha channel. The code is released under the MIT License and is not open source.