What could cause a second degree burn on the scalp during a blow dry?

Holding the blow dryer on the scalp for too long can indeed cause a second-degree burn. Second-degree burns affect both the outer layer of skin (epidermis) and the underlying layer (dermis). When a blow dryer is held in one spot too long, the high temperature can result in overheating of the skin, leading to the formation of blisters and significant pain, which are typical characteristics of a second-degree burn.

It's important to remember that proper techniques in blow drying, such as maintaining a safe distance from the scalp and moving the dryer continuously, can help prevent such injuries. Other factors, such as the use of heat settings or attachments, may play a role in the overall safety of the blow drying process, but they are less likely to directly cause burns if used properly.