© 2020 Elsevier LtdHoly temples represent a unique type of buildings due to their large inner space, purpose, and intermittent use. This review summarizes the essential knowledge embodied in the numerous research studies performed on the topics of thermal comfort, indoor air quality, and energy consumption in temples. The focus is on churches and mosques as two frequent types of temples, but the findings apply also to other temples with similar architectural and occupancy characteristics. The review has revealed that even though the topics of thermal comfort, indoor air quality and energy consumption are interrelated, only one of the studies investigated all of them simultaneously. Though the energy consumption in temples is often high, this may not guarantee that a comfortable indoor environment is attained. Problems with thermal comfort frequently occur under severe climatic conditions. Passive measures such as thermal insulation, shading, using fans, cross-ventilating as well as innovative technical systems and operation strategies have been devised to improve the thermal conditions. It was found that the air quality deteriorates rapidly during prayers and natural ventilation by openings is usually not enough to ventilate the space. Despite that, the amount of research on indoor air pollutants and ventilating solutions in temples is scarce relative to the associated health and comfort costs. Studies on the use of renewable energy in temples are also lacking although the limited research on this topic indicates the feasibility of this energy-saving solution.