A heat reflector is used to retain the radiated heat from a fire in the outdoors. This allows you to stay warm, while also using a smaller amount of wood which will make your life a bit easier. There are many variations of these. Essentially anything that will bounce the heat from the fire back to you will work. Rockface, wood reflector, etc. This specific reflector was on the small side since we had a pretty good camp set up with favorable weather conditions. Between the airflow from wind and draft, we had a well aired fire. We did cover the back side of the reflector with Pine boughs should any inclement weather turn up suddenly, but that is optional. If you built a thicker wall that would not be necessary. Be sure not to enclose the fire if you use a V design like me, one because you may catch the reflector on fire, but 2 because you can minimize airflow. Additionally, if its really cold, you can build a heat reflector behind yourself as well.