Cold Sweat is a mod for Minecraft 1.20, 1.19, 1.18, and 1.16 that adds a comprehensive temperature system to the game. This is the public repository for the project on CurseForge:
https://www.curseforge.com/minecraft/mc-mods/cold-sweat
This project is completely open for reference and reproduction as per our GNU GPL 3.0 license; HOWEVER, any project that directly samples code, assets, or otherwise from Cold Sweat must also list their project under the GNU General Public License 3.0 and attribute this project (also defined in the license). This does not include mods that use Cold Sweat as a library (i.e. for inter-mod compat) and thus use functions from the mod's code, so long as they do not directly redistribute any part of the project.
Documentation for 3rd-party integration with Cold Sweat can be found here (WIP, but most important things are documented):
https://mikul.gitbook.io/cold-sweat/
The current documentation is only designed for 1.20, but it should be useable for other Minecraft versions with some adaptation.
(i.e. implementation "curse.maven:cold-sweat-506194:5011469-sources-5011470" gives you version 2.2.5 for 1.20 with the sources jar for your development environment)