Facing the Heat: Utilizing the Internet of Things (IoT) to Enhance Preparedness Against Extreme Heat Events in Canadian Households

Abstract

\textbf{Background} Heat waves pose a severe and growing health risk in Canada, with an estimated 17 million people likely to experience extreme heat in the coming decades. These risks are heightened in urban areas, where the urban heat island effect exacerbates dangerous temperatures. Extreme heat events are increasingly frequent, intense, and widespread, with record-breaking heat waves affecting almost every region globally. Despite increasing awareness, many of the dangers associated with extreme heat are only now being fully realized. This work addresses data gaps related to indoor heat vulnerability needed to create safe indoor conditions. Education and early warnings are critical to protecting the population, especially vulnerable groups. Extreme heat is a climate justice issue, disproportionately affecting marginalized groups with fewer resources to cope.

\textbf{Methods} This study used smart thermostats (ecobee) to collect real-time indoor temperature data, developing a hyperlocal alert system for indoor heat risks. First, we analyzed ecobee's "Donate Your Data" dataset to identify homes without air conditioning and to explore indoor and outdoor temperature differences during the 2018 Quebec heat wave. Next, a scoping review assessed the use of IoT or similar devices, focusing on climate-related impacts. Canadians were surveyed through Google Opinion Rewards to evaluate their understanding of heat waves and preferences for receiving heat-related information. Online discourse about heat waves was analyzed using Latent Dirichlet Allocation (LDA) topic modelling on tweets from Twitter (now X), via natural language processing (NLP), and manually using an inductive approach to observe emerging narratives and themes. Finally, in the summer of 2022, a full-scale deployment of smart thermostats was conducted in community housing without air conditioning in collaboration with housing and public health organizations. Indoor temperature data was collected from 70 British Columbia and Ottawa homes, with results shared via daily emails and an elastic dashboard. Three surveys captured details on building types, resident behaviours, and heat-related habits.

\textbf{Results} The scoping review found that using IoT and low-cost sensors for indoor heat monitoring is an emerging field that could strengthen early warning systems and heat response efforts. The survey results showed that most Canadians preferred to receive heat wave information online, with income correlating to the usage of mobile devices. Older demographics still preferred traditional media like TV, radio, and newspapers. Online discussions centred around activities, personal experiences, advice, and warnings related to heat waves. Emerging trends of climate denial were present in both survey and tweet samples. Indoor temperature data revealed that homes frequently exceeded emerging threshold recommendations of 26°C and 31°C, with some homes recording temperatures as high as 38°C on non-heat wave days. Participants in British Columbia were better prepared and had higher heat safety awareness than other regions. This is the first Canadian study to explore the use of IoT smart thermostats in near-real-time indoor temperature monitoring to protect vulnerable populations from extreme heat. Significant differences were observed between indoor and outdoor temperatures ($P <0.001$).

\textbf{Discussion and Conclusion} This work shows the potential of IoT devices and social media to improve real-time monitoring and inform evidence-based public health interventions for extreme heat. The widespread adoption of smart thermostats in Canadian homes and the prevalence of social media provide valuable opportunities to address existing data and knowledge gaps. However, the persistence of climate misinformation and denial challenges public health communication efforts. Indoor heat is a public health and equity issue related to poverty, substandard housing, urban planning, and energy access. These interconnected issues must be considered in policy frameworks to protect vulnerable populations. Low-cost sensors and solutions, such as natural ventilation mobile alerts, could support the response to heat health by addressing a data gap. Rapidly analyzing these areas is important as digital spaces evolve to support public health communication. Policymakers must take immediate action to prevent unsafe indoor conditions and protect marginalized communities from the growing threat of extreme heat.