Self-pacing as a protective mechanism against the effects of heat stress

Objective: Self-pacing or avoidance of physiological strain by adjustment of work rate may be an important protective behaviour for manual workers in severe thermal conditions. Data were gathered at a number of industrial sites in the United Arab Emirates to assess whether self-pacing takes place in these workers.Methods: Heart rate and aural temperature were monitored in 150 subjects for 12 h daily over 2 consecutive days. Environmental parameters were measured for quantification of heat stress by the thermal work limit.Results: There was no evidence of an effect of variation in environmental thermal stress on either average working heart rate or aural temperature.Conclusion: These studies provide evidence that self-pacing is a protective response to working in heat which does not require a highly informed workforce; recognition of this should form part of a holistic approach to management of heat stress in hot climates.