Dubai: As the summer heat builds up and more and more people stay indoors, at home or at the workplace, experts caution against a serious health threat stemming from poorly ventilated systems. Dr Ali Anwar Mohammad, Specialist Pulmonologist at Prime Healthcare Group, said, “Usually indoor air vents will have any kind of microbes or organisms such as moulds, mites, dust pollens, fungus, virus and bacteria in damp, dark and humid places within the system. With regular cleaning and airing, the vents are free of these organisms. However, if neglected, the lifespan of these organisms increases manifold and they multiply. This is especially significant as humidity levels are rising in summer and people are staying indoors,” he cautioned.