Comparison of Fatigue in Varying Hot Environments

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT04624919

Enrollment

Registered

2020-11-12

Start date

2019-12-10

Completion date

2021-06-30

Last updated

2021-10-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hyperthermia

Brief summary

The purpose of this study is to determine the impact of varying hot environments on physiological and perceptual fatigue during work.

Detailed description

After providing written informed consent and screening, subjects will complete two experimental visits during which they will complete treadmill work in either a hot/dry or warm/humid environment.

Interventions

OTHERHot/Dry

Work is completed in a hot/dry environment.

OTHERWarm/Humid

Work is completed in a warm/humid environment

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

OTHER

Masking

NONE

Intervention model description

Randomized, counterbalanced crossover design

Eligibility

Sex/Gender

ALL

Age

18 Years to 39 Years

Healthy volunteers

Yes

Inclusion criteria

* 18-39 y old men and women * Self-reported to be healthy

Exclusion criteria

* History of any cardiovascular, neurologic, renal, or metabolic disease * Current tobacco use or regular use within the last 2 years * Current musculoskeletal injury * Taking medications with known thermoregulatory or cardiovascular effects (e.g., aspirin, acetaminophen, ibuprofen, beta blockers, diuretics, psychotropics, etc.) * Currently pregnant or breastfeeding, or planning to become pregnant during the study * Inability to follow the rules of the protocols or understand the consent form * Contraindications of consuming a core temperature monitoring pill

Design outcomes

Primary

Measure	Time frame	Description
Smoothness of movement	90 minutes	The variable, jerk, determines smoothness or unevenness of physical movement during work. This is measured using accelerometers placed along the spine, ankle, and shoulder.
Energy Expenditure	90 minutes	The amount of energy the body is expending during work. This is measured using indirect calorimetry.

Secondary

Measure	Time frame	Description
Perceptual fatigue	90 minutes	The degree of fatigue that the subjects perceive during work. This is measured using a subjective likert 0-10 scale named the Fatigue Scale with 0 indicting no fatigue at all and 10 indicating completely fatigued.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 5, 2026