What can excessive heat from laser treatments cause in the skin?

Excessive heat from laser treatments can indeed lead to scarring in the skin. When laser energy is improperly calibrated or if the skin is overly exposed to the heat during a procedure, it can result in damage to the skin's layers. This damage may provoke an inflammatory response that, if severe enough, could lead to fibrosis, or the formation of scar tissue. Scarring is a common risk associated with laser treatments, particularly when the heat affects the dermis significantly or when healing processes are disrupted.

The other options do not result from excessive heat. Skin tightening typically occurs from controlled heating that stimulates collagen production rather than excessive heat, while enhanced blood flow and increased melanin production would usually not be a direct consequence of heat damage but can result from other factors or mild heat exposure.