I have personal experience using Xternal on sunburn. Applied to the back of my neck, all signs of the burn where gone the next day.
I have also heard stories of people using Xternal on more serious burns - as you might get from an oven while cooking - with excellent results.
It's interesting that the ingredients of Xternal are not the usual formulation of high CBD that many others have taken, but rather full spectrum cannabinoids. CBD is known to have anti-inflammatory properties, but one could argue that the Xternal product with their different approach works as well or better than high CBD formulations.
I would be curious to hear a doctors opinion on this.