The strategies and techniques of heating, cooling and ventilation are different for mosques than for other types of buildings because of their large volumes, intermittent use, and hosting a great number of congregation members. We investigate potentially feasible strategies to improve thermal comfort and air quality in a representative urban mosque located in a warm temperate climate. These strategies include opening windows, turning on air conditioners, using fans, and their combinations while considering the effect of occupancy. The overall thermal sensation, draught risk, and CO2 concentration were experimentally studied during the holy month of Ramadan. In the naturally ventilated mosque, opening windows considerably improved the air quality but increased the indoor relative humidity. Using fans has the potential to enhance the air quality by reducing pollution in the occupied zone, and to improve the overall thermal sensation. The drawback of using fans was the risk of discomfort due to the peaks in air speed caused by rotation of the fans, which must be prevented to attain comfortable conditions. Turning the air conditioning on during prayers was not an efficient strategy to improve thermal comfort. It is recommended to consider pre-cooling of the mosque and keep air conditioners off during prayers.