“…Numerous researchers have suggested that both exercise (i.e., physical work) and cold (e.g., air temperature below 12 o C) may be potentially immunosuppressive, and in combination may contribute to meaningful reductions in immunity and increased risk of respiratory infection, especially for people working in some occupations (e.g., construction, fishing, food processing) [2,6,7,8,9]. In line with this, it has been shown that people working in cold environments suffer upper respiratory tract infections more frequently (URTI; including the common cold, pharyngitis, epiglottitis and laryngotracheitis) than the general population [10,11], for which respiratory tract infections are the most frequent cause of illness [12,13]. Since URTI is highly prevelant, it is important to find markers linked -directly or indirectly -to these infections with the aim of performing future interventions to reduce the prevelance and/or duration of illness.…”