Occupational Heat Stress on Workers' Productivity

NCT04160728 | Completed

• 1 other identifier: 7. Workers' heat stress
• Study Type: interventional
• Target: 248
• Locations: 1 country
• Sites: 1

Brief Summary

Workplace heat exposure affects billions of people during their everyday work activities. Occupational heat stress impairs workers' health and capacity to perform manual labour. Therefore, the aim of this study was to observe the heat strain experienced by workers in occupational settings and test different strategies to mitigate it during actual work shifts in agriculture, manufacture, tourism, construction, and other services.

Conditions

Risk of Heat Stress

Keywords

heat stress; heat strain; productivity; labor; occupation; work; thermal

Outcome Measures

Primary Outcomes (9)

• Heart rate

  Heart rate data were continuously monitored using a Polar Team system (Polar® Team 2, Polar Electro Oy, Kempele, Finland

  12-hour workshift

• Mean skin temperature

  Temperature at the skin surface area was continuously monitored using iButton sensors (type DS1921 H, Maxim/Dallas Semiconductor Corp., USA)

  12-hour workshift

• Core body temperature

  Core body temperature was assessed throughout the entire work shift using telemetric capsules (e-Celsius, BodyCap, Caen, France) that was given to the workers to ingest prior to their work shift

  12-hour workshift

• Urine specific gravity to assess the hydration status

  Urine was obtained from the participants pre and post the 12-hour work shift. Urine specific gravity (single assessment-no units) was assessed using a refractometer (PAL-10S, ATAGO CO., LTD., Fukaya, Saitama Prefecture, Japan). Urine color was assessed using a urine color scale

  Pre and post the 12-hour workshift

• Labour effort

  Actual time (single assessment-hours) of working effort and break time during the 12-hour work shift. They were assessed by time-motion analysis (video) or real time task analysis (surveillance) on a second by second basis

  12-hour workshift

• Thermal comfort

  Thermal comfort was assessed via the thermal comfort scale (1 = comfortable; 5 = extremely uncomfortable).

  At baseline, every two hours up until the end of the 12-hour workshift

• Thermal sensation

  Thermal sensation was assessed via the thermal sensation scale (-3 = cold; +3 = hot)

  At baseline, every two hours up until the end of the 12-hour workshift

• Perceived exertion

  Perceived exertion was assessed via the Borg 20th Scale (6 = no exertion at all; 20 = maximal exertion)

  At baseline, every two hours up until the end of the 12-hour workshift

• Heat Strain Score Index

  Heat Strain Score Index was assessed via the 18-question Heat Strain Score Index questionnaire that assess the heat and physiological strain

  At the end of the 12-hour work shift

Study Arms (6)

Work/ rest scenario

EXPERIMENTAL

For every hour of work, the participants were asked to take 3-10 minutes break in the shade.

Other: Work/ rest scenario

Hydration scenario

EXPERIMENTAL

Participants were asked to consume at least 750ml of water or ice-slushies for every hour of work.

Other: Hydration scenario

Clothing scenario

EXPERIMENTAL

Participants were asked to wear different types of clothing during the work shift i.e. ventilated garments, white breathable coveralls, clothing with water submerged parts.

Other: Clothing scenario

"E-carts" scenario

EXPERIMENTAL

Participants that were involved in manual labor by carrying heavy weights were provided with "e-carts" (automated carrying vehicles)

Other: "E-carts" scenario

Business as usual scenario

SHAM COMPARATOR

No interference with the usual work day of the participants.

Other: Business as usual scenario

Sham evaluation

SHAM COMPARATOR

Participants were monitored during a usual day of work shift while sham measurements were recorded in order for them to get familiarized with the study environment.

Other: Sham evaluation

Interventions

Work/ rest scenario OTHER

For every hour of work, the participants were asked to take 3-10 minutes break in the shade.

Work/ rest scenario

Hydration scenario OTHER

Participants were asked to consume at least 750ml of water or ice-slushies for every hour of work

Hydration scenario

Clothing scenario OTHER

Participants were asked to wear different types of clothing during the work shift i.e. ventilated garments, white breathable coveralls, clothing with water submerged parts

Clothing scenario

"E-carts" scenario OTHER

Participants that were involved in manual labor by carrying heavy weights were provided with "e-carts" (automated carrying vehicles)

"E-carts" scenario

Business as usual scenario OTHER

No interference with the usual work day of the participants

Business as usual scenario

Sham evaluation OTHER

Participants were monitored during a usual day of work shift while sham measurements were recorded in order for them to get familiarized with the study environment

Sham evaluation

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Workers in the industries of agriculture, construction, manufacture, , tourism, or other services

You may not qualify if:

• Workers under the age of 18 or non-experienced workers

Sponsors & Collaborators

• Petros Dinas: lead

Study Sites (1)

FAME Lab, Department of Exercise Science, University of Thessaly

Trikala, Thessaly, 42100, Greece

Location

Related Publications (1)

• Ioannou LG, Tsoutsoubi L, Mantzios K, Gkikas G, Agaliotis G, Koutedakis Y, Garcia-Leon D, Havenith G, Liang J, Arkolakis C, Glaser J, Kenny GP, Mekjavic IB, Nybo L, Flouris AD. The Impact of Workplace Heat and Cold on Work Time Loss. J Occup Environ Med. 2025 Jun 1;67(6):393-399. doi: 10.1097/JOM.0000000000003332. Epub 2025 Feb 7.

  PMID: 39965897 DERIVED

MeSH Terms

Conditions

Heat Stress Disorders

Interventions

Commerce

Condition Hierarchy (Ancestors)

Wounds and Injuries

Intervention Hierarchy (Ancestors)

Technology, Industry, and Agriculture

Study Officials

• Andreas Flouris

  andreasflouris@gmail.com

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Researcher in human physiology

Study Record Dates

• First Submitted: November 7, 2019
• First Posted: November 13, 2019
• Study Start: July 5, 2019
• Primary Completion: August 5, 2019
• Study Completion: August 5, 2019
• Last Updated: November 29, 2023

Record last verified: 2023-11

Data Sharing

• IPD Sharing: Will not share

Locations

GR (1)