- Bellows

Created from sticks and leather, bellows is an item that can turn normal fire into a High Fire that is suitable for heating up materials for forging. Note that High Fire will turn back to a normal fire after short time, so keep those bellows handy. You can blow on High Fire again to extend its life a bit.

- Smithing Tongs

Tongs are used to pick up hot iron ingots and tool heads without taking damage from heat. If you have at least one spare pair of tongs in your inventory and you pick up any of the mod's hot materials, the tongs will automatically pick up that item.

- Smithing Hammer

To forge any tool head from hot material you will need a Smithing Hammer. You will need to click with a hammer on a Smithing Anvil five times to finalize any of the new Forging recipes.

- Smithing Anvil

This is the core block of the mod, Smithing Anvil lets you perform Forging recipes by arranging ingredients in a grid similar to the one of a crafting table and then finalizing the recipe by clicking with a Smithing Hammer on the anvil several times.

Besides changing the way you make iron, gold and diamond tools, Hot Iron also introduces a unique way to make stone tools. First, you will need to chip on some exposed stone with a Flint until the stone turns into cobblestone, dropping a single Rock. 

After you gather some rocks, you will need to take those rocks both in your main and off-hand and knap them until you get a Knapped Rock.

Now you can combine knapped rocks to get stone tool heads which you then combine with a stick to get your Stone Tools!

- Quark

Quark breaks stone tool recipes, reverting them to vanilla/Quark ones. This can be fixed manually by making a datapack with a copies of Hot Iron's stone tool recipes and copies both Quark and vanilla recipes as blank files

- Any mod that changes vanilla armor and tool recipes can potentially break mod's corresponding recipes

If it happens, you can fix that fairly easily by making a datapack that forcefully overrides broken recipes