Yes, a handheld fan can provide a cooling effect for the person using it. While the fan itself doesn't lower the temperature of the air, it creates airflow that helps to increase the evaporation of moisture from the skin, leading to a perceived cooling sensation.
When you're hot, your body naturally produces sweat as a cooling mechanism. The movement of air from a handheld fan accelerates the evaporation of sweat from your skin, which can help to dissipate heat and make you feel cooler. The airflow generated by the fan also helps to create a breeze, which can provide some relief by displacing the warm air surrounding your body.
However, it's important to note that a handheld fan doesn't actually lower the ambient temperature in the environment. It simply provides localized cooling by enhancing the evaporative cooling process on your skin. Additionally, the effectiveness of a handheld fan may vary depending on factors such as humidity levels and the temperature of the surrounding air. In extremely hot and humid conditions, the cooling effect of a handheld fan may be less noticeable.