Which of the following is NOT considered a protective mechanism of the body?

Body temperature is not classified as a protective mechanism of the body in the same way that mucus, skin, and tears are. Protective mechanisms are physical or biochemical defenses that help the body prevent infection and injury.

Mucus, for example, acts as a barrier and traps pathogens and dust particles, preventing them from entering the respiratory system. Skin serves as the body's primary physical barrier against environmental threats, including pathogens. Tears contain enzymes and antibodies that help to wash away irritants and provide antimicrobial action to protect the eyes.

While body temperature plays a role in the overall function of the immune system—such as in the response to infection, where it can rise to create an unfavorable environment for pathogens—it does not serve as a direct protective barrier in the same explicit manner as the other options listed. Therefore, it is categorized differently within the body's response mechanisms.