Now, we can not use forge fluids, because they do not carry information like "heat" (no idea if that is true). So, maybe we could somehow adapt EU api to do it?
Forge Fluids can store Heat using NBT Data. I would disrecommend that as not all Mods watch it, and because Fluids with different NBT don't stack together in a Pipe. However you can make FLuids like "hotwater" and "veryhotwater" or just "steam".