First degree damages the top layer of skin, the typical sunburn is first degree. Second degree penetrates deeper and can involve things like blistering, it should receive first aid, but otherwise is likely fine. Third degree destroys all layers of skin, may appear black, and likely doesn’t hurt due to destroyed nerves, it should be accompanied with an er (a&e for the brits) visit. Fourth degree destroys all layers of skin and some stuff under it, it can be life threatening.

I believe first or second degree burns are possible in this scenario, but third feels like an exaggeration