How to control heat on a Bunsen burner?

To control the heat on a Bunsen burner, adjust the air supply by turning the collar at the base of the burner, which regulates the amount of air mixed with the gas. For a hotter flame, open the collar to allow more air in, resulting in a blue, hotter flame. For a cooler, yellow flame, close the collar to limit airflow. Additionally, adjust the gas flow using the gas valve to fine-tune the flame's intensity.