A Heat Management Device is an accessory used in most of your favourite lounges and by shisha enthusiasts. The HMD is generally made from aluminium materials to give off heat to your bowl. This is a replacement for your regular foil and helps bake your tobacco evenly within your bowl. It also ensures a longer lasting session by creating a stronger barrier between the coal and the tobacco, regulating the heat and producing better smoke content. Some HMD's will have a mechanism which allows you to increase or decrease heat to your bowl by adjusting the airflow that interacts with your charcoal.