International Archives of Occupational and Environmental Health (2018) 91:705–715
Occupational heat exposure among municipal workers
Christopher K. Uejio
· Laurel Harduar Morano
· Jihoon Jung
· Kristina Kintziger
· Meredith Jagger
· Tisha Holmes
Received: 26 June 2017 / Accepted: 22 May 2018 / Published online: 5 June 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Purpose Outdoor workers face elevated and prolonged heat exposures and have limited access to air-conditioned spaces.
This study’s overarching research aim is to increase knowledge of municipal worker heat exposure and adaptation practices.
The study’s sub-objectives are: (1) quantifying exposure misclassiﬁcation from estimating personal heat exposure from
the oﬃcial weather station; (2) surveying worker’s knowledge and practices to adapt to extreme heat; and (3) relating heat
exposure and adaptation practices to self-reported thermal comfort.
Methods Participants wore a personal heat exposure sensor over 7 days from June 1st to July 3rd, 2015 in Tallahassee,
Florida US. Next, participants conﬁrmed the days that they wore the sensor and reported their daily thermal comfort and
heat adaptations. Finally, participants completed an extreme heat knowledge, attitudes, and practices survey.
Results Some participants (37%) experienced hotter and more humid conditions (heat index > 2) than the weather station.
The most common heat adaptations were staying hydrated (85%), wearing a hat (46%), and seeking shade (40%). During
work hours, higher temperatures increased the odds (odds ratio: 1.21, 95% conﬁdence interval: 1.03–1.41, p = 0.016) of a
participant feeling too hot. Shifting work duty indoors made workers to feel more comfortable (odds ratio: 0.28, 95% con-
ﬁdence interval: 0.11–0.70, p = 0.005).
Conclusion In hot and humid climates, everyday, heat exposures continuously challenge the health of outdoor workers.
Keywords Extreme heat · Outdoor workers · Adaptation · Temperature · Thermal comfort
The United States of America’s (US) summertime
(May–September) rate of heat emergency department visits
was 21.5/100,000 people per year over 2006–2010 based on
the Agency for Healthcare Research and Quality’s Nation-
wide Emergency Department Sample (Hess et al. 2014).
Certain groups are more vulnerable to heat-related illness
including the poor, young children, older adults, people with
pre-existing conditions (e.g., heart disease, poor blood cir-
culation, diabetes, chronic obstructive pulmonary disease,
and mental illness) or people taking medications that alter
thermoregulation (Centers for Disease Control and Preven-
tion and Environmental Protection Agency 2016; Gronlund.
2014; Uejio et al. 2011). Outdoor workers engaged in agri-
culture, construction, ﬁreﬁghting, manufacturing, military,
or resource extraction also face heightened risks (Gubernot
et al. 2014; Xiang et al. 2014). Such workers face prolonged
heat exposures from outdoor conditions or indoor environ-
ments with limited air conditioning or ventilation. Physical
* Christopher K. Uejio
Department of Geography, Florida State University, Bellamy
Building Room 323, 113 Collegiate Loop, PO Box 3062190,
Tallahassee, FL 32306, USA
Department of Epidemiology, Gillings School of Global
Public Health, University of North Carolina at Chapel Hill,
170 Rosenau Hall CB #7400, 135 Dauer Drive, Chapel Hill,
NC 27599, USA
Department of Public Health, University of Tennessee, 1914
Andy Holt Avenue, HPER 375, Knoxville, TN 32996, USA
Oﬃce of Injury Prevention, Texas Department of State
Health Services, 1100 West 49th Street, Austin, TX 78714,
Chattanooga, TN, USA
Department of Urban and Regional Planning, Florida State
University, Bellamy Building, Room 333, 113 Collegiate
Loop, Tallahassee, FL 32306, USA