An unconditioned reflex is a natural, automatic response to a specific stimulus that does not require prior learning or conditioning. For example, when a person touches something hot, they instinctively pull their hand away. This reflex action is immediate and occurs without conscious thought, ensuring quick reactions to potentially harmful situations. Unconditioned reflexes are essential for survival and are present in many living organisms. They are often contrasted with conditioned reflexes, which are learned responses developed through experience, as demonstrated in the work of Ivan Pavlov with his famous experiments involving dogs and salivation.