Which of the following is NOT a sign of infection?

Excessive fatigue is not typically classified as a direct sign of infection. While fatigue can be a symptom associated with various illnesses, it is not a localized sign like heat, redness, or pus. Infections often manifest through specific local signs that indicate inflammation, which include increased warmth (heat) at the site of infection, redness from increased blood flow, and the presence of pus that results from the accumulation of white blood cells and cellular debris. These localized responses are part of the body's immune response to infections, making them significant indicators in determining the presence of an infection.