JMIR Publications

ABSTRACT

Background:

The objective of this study is to validate whether smart thermostats can be used to measure indoor temperature during a heat wave and identify households at risk for dangerous indoor temperatures. Climate change, driven by human activity, is rapidly changing our environment and posing an increased risk to human health. Local governments must adapt their cities and prepare for increased periods of extreme heat; ensuring marginalized populations do not suffer detrimental health outcomes. Heat warnings traditionally rely on outdoor temperature data which may not reflect the indoor temperatures experienced by individuals. Smart thermostats coupled to the Internet of Things (IoT) could be a novel and highly scalable data source for heat wave monitoring.

Objective:

The objective of this study is to validate whether smart thermostats can be used to measure indoor temperature during a heat wave and identify households at risk for dangerous indoor temperatures.

Methods:

We explored indoor temperatures recorded from ecobee smart thermostats during the Quebec heat waves of 2018 that claimed 66 lives. Outdoor temperature data from seven Environment Canada weather stations and indoor temperatures from 400 households were aggregated and visualized with RShiny. We performed statistical analyses to compare indoor temperatures differences between A/C and non-A/C households from June 1 to August 31, 2018.

Results:

Ecobee data found significant indoor temperature differences between households with and without A/C on both heat wave and non-heat wave days. Households without A/C consistently recorded daily temperatures above the safe threshold of 26C. Unsafe temperatures persisted for an average of four hours per day. Results were consistent with current literature on buildings warming and retaining heat during heat waves and contributing to increased risk of heat-related illnesses.

Conclusions:

The results demonstrate that indoor temperatures can be captured in real-time using smart thermostats across a large population. When integrated with local heat health action plans, this data can be used to strengthen existing heat alert response systems and enhance emergency medical service responses.