You can get fancy and use an infrared thermometer to check the heat emitted from your coals or wood! But I just go for it and keep an eye on things. You are aiming for a nice and hot 450-500°F to cook the pizza fast. Do not let your wood flare up or you will absolutely burn your pizza. Start cooking with the lid on but you can always finish with it off. Keeping it on and a heat source on top is how you will make sure the cheese melts.