**Core Concept**
Ruptured skin caused by excessive heat leads to the formation of bullae, which are large blisters filled with fluid. This condition is known as heat burn or heat blister. The underlying mechanism involves damage to the epidermal-dermal junction due to thermal injury.

**Why the Correct Answer is Right**
Heat-induced damage to the skin results in the breakdown of the epidermal-dermal junction, leading to the formation of bullae. This is due to the denaturation of proteins in the skin, causing loss of tissue integrity. The dermal-epidermal junction is rich in collagen and elastin fibers, which are sensitive to heat. When exposed to excessive heat, these fibers are damaged, resulting in the separation of the epidermis from the dermis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not describe the characteristic feature of heat-induced skin damage. Heat burn or heat blister is a distinct clinical entity that involves the formation of bullae.
**Option B:** This option is incorrect as it describes a different type of skin injury. Frostbite involves the damage to skin and underlying tissues due to extreme cold temperatures, resulting in the formation of ice crystals within the tissues.
**Option C:** This option is incorrect as it describes a different type of skin condition. Erythema multiforme is a skin condition characterized by the presence of target lesions, which are not associated with heat-induced skin damage.
**Option D:** This option is incorrect as it describes a different type of skin injury. Electrical burns involve the passage of electrical current through the body, resulting in thermal injury to the skin and underlying tissues.

**Clinical Pearl / High-Yield Fact**
Heat-induced skin damage can be prevented by taking regular breaks in shaded areas, wearing protective clothing, and staying hydrated. It is essential to recognize the signs of heat-related illnesses, such as heat exhaustion and heat stroke, and seek medical attention promptly if symptoms persist or worsen.

**Correct Answer:** C. Bullae formation is a characteristic feature of heat-induced skin damage.