Project Coolbit: Can your watch predict heat stress and thermal comfort sensation?

Author

Negin NAZARIAN
Sijie LIU
Manon KOHLER
Jason LEE
Clayton MILLER
Winston T. L. CHOW, Singapore Management UniversityFollow
S. B. B. ALHADAD
Alberto MARTILLI
Matias QUINTANA
Lindsey SUNDEN
Lindsey NORFORD

Publication Type

Journal Article

Version

publishedVersion

Publication Date

2-2021

Abstract

Global climate is changing as a result of anthropogenic warming, leading to higher daily excursions of temperature in cities. Such elevated temperatures have great implications on human thermal comfort and heat stress, which should be closely monitored. Current methods for heat exposure assessments (surveys, microclimate measurements, and laboratory experiments), however, present several limitations: measurements are scattered in time and space and data gathered on outdoor thermal stress and comfort often does not include physiological and behavioral parameters. To address these shortcomings, Project Coolbit aims to introduce a human-centric approach to thermal comfort assessments. In this study, we propose and evaluate the use of wrist-mounted wearable devices to monitor environmental and physiological responses that span a wide range of spatial and temporal distributions. We introduce an integrated wearable weather station that records a) microclimate parameters (such as air temperature and humidity), b) physiological parameters (heart rate, skin temperature and humidity), and c) subjective feedback. The feasibility of this methodology to assess thermal comfort and heat stress is then evaluated using two sets of experiments: controlled-environment physiological data collection, and outdoor environmental data collection. We find that using the data obtained through the wrist-mounted wearables, core temperature can be predicted non-invasively with 95 percent of target attainment (PTA) within 0.27C. Additionally, a direct connection between the air temperature at the wrist (Ta,w) and the perceived activity level (PAV) of individuals was drawn. We observe that with increased Ta,w, the desire for physical activity is significantly reduced, reaching "Transition only" PAV level at 36C. These assessments reveal that the wearable methodology provides a comprehensive and accurate representation of human heat exposure, which can be extended in real-time to cover a large spatial distribution in a given city and quantify the impact of heat exposure on human life.

Keywords

heat stress, thermal comfort, wearable technologies, personalized heat exposure, urban climate

Discipline

Computer Sciences | Environmental Sciences | Place and Environment

Research Areas

Integrative Research Areas

Publication

Environmental Research Letters

Volume

18

Issue

3

First Page

1

Last Page

16

ISSN

1748-9326

Identifier

10.1088/1748-9326/abd130

Publisher

IOP Publishing

Embargo Period

3-30-2021

Citation

NAZARIAN, Negin, LIU, Sijie, KOHLER, Manon, LEE, Jason, MILLER, Clayton, CHOW, Winston T. L., ALHADAD, S. B. B., MARTILLI, Alberto, QUINTANA, Matias, SUNDEN, Lindsey, & NORFORD, Lindsey.(2021). Project Coolbit: Can your watch predict heat stress and thermal comfort sensation?. Environmental Research Letters, 18(3), 1-16.

Available at: https://ink.library.smu.edu.sg/soss_research/3285

Copyright Owner and License

Authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Additional URL

https://doi.org/10.1088/1748-9326/abd130