There are several ways to remove heat marks from granite:

1. Use baking soda: Mix baking soda and water to make a paste. Apply the paste to the heat mark and let it sit for a few hours. Then, rinse the area with water and dry it with a clean towel.

2. Use a poultice: Make a poultice by mixing baking soda and water to make a thick paste. Apply the poultice to the heat mark and cover it with plastic wrap. Let it sit for 24 hours, then remove the plastic and let the poultice dry. Once the poultice is dry, scrape it off with a plastic scraper.

3. Use a heat gun: Use a heat gun on the lowest setting to gently warm the surface of the granite. As you warm the granite, gently rub the heat mark with a clean cloth. Be careful not to overheat the granite or damage it with the heat gun.

4. Use a granite cleaner: Apply a granite cleaner to the heat mark and let it sit for a few minutes. Then, wipe the area with a damp cloth and dry it with a clean towel.

Note: It is important to avoid abrasive cleaners or tools, such as steel wool or scrubbing pads, as they can scratch or damage the granite surface.