## 1 Introduction  
Indoor environment quality (IEQ) in buildings incorporates indoor air quality (IAQ), acoustics, thermal comfort, and lighting [1]. It is well known that poor IEQ has a negative effect on occupational health, particularly on children and old people. Poor IAQ is a significant problem which affects particularly the underprivileged people in the world, as they remain most exposed, presenting itself as a critical problem for global health such as tobacco use or the problem of sexually transmitted diseases [2]. The Environmental Protection Agency (EPA) is responsible for indoor and outdoor air quality supervision in the United States. The EPA assessment recognises that IAQ pollutants concentration can be up to 100 times greater when compared with the outdoor pollutants concentration levels and established poor air quality, which are in the top five environmental risks to global health [3]. Indoor living environments include several types of spaces and workplaces such as offices, hospitals, public service centres, schools, libraries, leisure spaces and also the cabins of vehicles [4]. In particular, schools are an essential place to monitor. Typically, the large number of occupants, the time spent indoors,and the higher density of occupants justifies the need to develop automatic supervision systems to provide a healthful and productive workplace for students, teachers and school staff [5]. Buildings are responsible for 40% of the global energy consumption and 30% of the CO\({}_{2}\) emissions. Thermal comfort assurance is related to a substantial percentage of the referred energy consumption. The adoption of personalised conditioning systems is apparently a reliable approach to improve user acceptability with the environment thermal conditions since thermal comfort is a complicated subject with several interrelated aspects that need to be understood [6]. Currently, IEQ in buildings is based on random sampling. However, these procedures are only providing information relating to a specific sampling and are devoid of details of spatio-temporal variations, which are particularly relevant in laboratory tests such as thermography experiments. The fundamental concept of the Internet of Things (IoT) is the pervasive presence of several types of devices with communication and collaboration skills between them to reach a mutual purpose [7]. The IoT will not only improve everyday life behaviours and activities in different areas such as smart homes, assisted living environments and smart-health, but also in present innovative data and computational resources to develop novel software solutions [8]. One of the fields where the IoT plays a significant role is IAQ monitoring [9]. The rapid increasing of Information and Communication Technologies (ICTs) and IoT proliferation offer significant opportunities in the development of healthcare information systems. However, challenges still exist in achieving safety, security and privacy for healthcare applications [10; 11]. Ambient Assisted Living (AAL) is a research area which studies the conceptualisation of an ecosystem of diverse kinds of sensors, computers, mobile gadgets, wireless networks and software development for enhanced personal healthcare supervision and telemedicine solutions [12]. At 2050, a significant proliferation of diseases will lead to high healthcare costs, lack of caregivers, dependency and notable social impact, because 20% of the world population will be aged 60 or over [13]. Most people (87%) prefer to stay in their houses and pay a significant charge for nursing care [14]. However, there are numerous difficulties in AAL solutions conceptualisation and development such as data structure, user-interface, human-computer communication, ergonomics, usability and accessibility [15]. Furthermore, the AAL solutions adopted by the aged population is influenced by social and ethical obstacles. Therefore, privacy and confidentiality are fundamental to AAL solutions' development.