Charcoal’s nemeses are humidity, CO2 and the cold. To reach maximum temperature, you must first have extremely dry charcoal. Secondly, the gas outlet on your appliance must be fully open. The CO 2 that builds up during combustion hinders the oxygenation of charcoal, so it must be let out of the appliance. Finally, the heat. An appliance like the Webber cannot reach as high a temperature as a ceramic egg comprised of several layers that reflect infrared radiation.