title: Does living and working in a hot environment induce clinically relevant changes in immune function and voluntary force production capacity?
abstract: This study investigated the effect of living (summer vs. winter) and working (morning vs. afternoon) in a hot environment on markers of immune function and forearm strength. Thirty-one healthy male gas field employees were screened before (between 05:30 and 07:00) and after their working day (between 15:30 and 17:00) during both seasons. Body core temperature and physical activity were recorded throughout the working days. The hot condition (i.e. summer) led a higher (p≤0.05) average body core temperature (~37.2 vs. ~37.4 °C) but reduced physical activity (-14.8%) during the work-shift. Our data showed an increase (p≤0.05) in lymphocyte and monocyte counts in the summer. Additionally, work-shift resulted in significant (p≤0.001) changes in leukocytes, lymphocytes and monocytes independently of the environment. Handgrip (p=0.069) and pinch (p=0.077) forces tended to be reduced from pre-to post-work, while only force produced during handgrip manoeuvres was significantly reduced (p≤0.05) during the hot compared to the temperate season. No interactions were observed between the environment and work-shift for any marker of immune function or forearm strength. In summary, working and living in hot conditions impact on markers of immune function and work capacity; however by self-regulating energy expenditure, immune markers remained in a healthy reference range.
authors.affiliation: Aspetar, Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance, Qatar.
authors.forename: Wade
authors.initials: W
authors.lastname: Knez
authors.forename: Olivier
authors.initials: O
authors.lastname: Girard
authors.forename: Sebastien
authors.initials: S
authors.lastname: Racinais
authors.forename: Andrew
authors.initials: A
authors.lastname: Walsh
authors.forename: Nadia
authors.initials: N
authors.lastname: Gaoua
authors.forename: Justin
authors.initials: J
authors.lastname: Grantham
mesh_terms: D000328:Adult; D001831:Body Temperature; D006358:Hot Temperature; D006801:Humans; D007107:Immune System / Q000502:physiology*; D018655:Lymphocyte Count; D008297:Male; D009000:Monocytes; D009043:Motor Activity / Q000502:physiology*; D000066388:Oil and Gas Industry; D052581:Pinch Strength / Q000502:physiology*; D012111:Residence Characteristics; D017132:Workplace; D055815:Young Adult