Make the biome biomesoplenty:hot_springs warm.

I might increase the temperature a little bit, but it's classified as a cold biome on purpose. That's how the mod author intended it. I will also consider making the water in that biome warm instead of cold, though.

I will also consider making the water in that biome warm instead of cold, though.

@MikulDev That would be great. Will you do it?

I did end up doing that, yes. I created a tag "forge:has_hot_water" that includes that biome by default. All biomes in that list will have warm water instead of cold water.