Wearing long pants while working outdoors in the tropics does not yield higher body temperatures


Correspondence to: Mr Wade Sinclair, Institute of Sport and Exercise Science, James Cook University, Townsville, Queensland 4811; e-mail: Wade.Sinclair@jcu.edu.au


Objective: To compare the thermoregulatory demands of outdoor workers wearing long or knee-length pants while working in situ in a tropical environment.

Methods: Fifteen male (35.8 ± 10.5 yr) outdoor Council workers completed their daily occupational duties (construction or gardening) in trials conducted six days apart: once wearing knee-length shorts (SHORTS) and once wearing full-length pants (PANTS). Body mass and hydration were assessed prior to and following each trial with core body (TC) and mean skin temperature (MST; weighted from sites: chest, arm, thigh and calf) assessed at 30-minute intervals throughout each trial.

Results: No significant differences between SHORTS and PANTS for TC, maximum TC, heart rate, MST or body mass changes. Skin temperature at the calf was greater for PANTS (33.8 ± 0.4°C) compared to SHORTS (32.9 ± 0.4°C; p<0.05). Hydration assessments identified 36.7% of participants commenced work hypohydrated while the average body mass lost throughout the workday was 2.5 ± 1.5%. Main effects of time were observed for heart rate and MST but no other assessed variable.

Conclusion: The additional exposed surface area available for heat exchange when wearing shorts is insufficient to elicit differences in thermoregulatory demands of outdoor employees under the assessed conditions.

Implications: These results suggest the use of SHORTS or PANTS can be determined by occupational duty requirements rather than risk of heat-related illness during very-light to moderate workloads completed under warm and humid environmental conditions.