Okay, so I know that the temperature is a highly debated topic, and I know that there are mods that already have a body temperature function, but I would really like to put it into my own mod. I'm new to this stuff, so patience and detail would be very much appreciated, thanks!
I have nothing working. Right now, what I want to happen is whenever a player enters a hot/cold biome, after like 2 minutes in said biome, their health starts slowly diminishing. So if the players wearing heavy armor, after about 4 minutes in the desert they would have lost 2 hearts, and it would keep going until they take the armor off. I thought the simplest way to do this was creating a potion effect, but I have no idea how to use the data in Minecraft to determine when the player should start feeling the effects.