A fan does not lower the temperature, but during a heatwave you can achieve a much cooler feeling with a few adjustments. It is mainly about timing, placement and a few small extras.
Keep the room dark and closed during the day
On hot days, it is usually more effective to keep the curtains or shutters closed during the day and keep the windows closed, especially on the sunny side. This keeps the heat largely outside and the fan has to move less warm air in the evening.
Ventilate and cool down in the evening and at night
As soon as the temperature outside drops below that inside, usually from the evening, you can open the windows and use the fan to draw cooler outside air in or blow warm inside air out. Do not point the device directly at your face all night: prolonged, direct airflow can cause a dry throat or irritated eyes in some people. Therefore, it is better to point the fan slightly away from you, or use an oscillating setting so that the airflow is spread across the room instead of continuously on a fixed point.
Combine with a damp cloth or bowl of water
A wet cloth or a bowl of water in front of the fan can slightly enhance the cooling effect, because evaporating water slightly cools the surrounding air. The effect is limited and works best in a dry environment, but it is a simple and inexpensive addition during the worst heat.
Use a timer or night mode if available
A fan that keeps running on the same setting all night can make unnecessarily much noise while you sleep. A model with digital controls, such as the AirFlow TV26G, makes it easier to adjust the setting without having to get out of bed every time.
Keep drinking enough
A fan helps against a stuffy feeling, but does not replace moisture. Make sure that you drink enough water during a heatwave, even at night, especially for the elderly and children who are less likely to indicate that they are thirsty.
Direct answer: keep the room dark and cool during the day, ventilate and use the fan mainly in the evening and at night when it is cooler outside, do not point the airflow directly at your face all night, and optionally combine with a bowl of water for extra cooling.
Looking for a fan for warm nights? Check out the AirFlow TV26G or the height-adjustable AirFlow AV25G on dynter.eu.