Exercise increases heat production. During exercise in both warm and cold conditions, the major dilemma is the dissipation of the heat produced from muscular activity. The use of clothing generally represents a layer of insulation and as such imposes a barrier to heat transfer and evaporation from the skin surface. In warm environments, additional clothing increases thermal insulation causing more rapid increases in temperature during exercise and imposes a barrier to sweat evaporation. However, clothing can serve a protective function by reducing radiant heat gain and thermal stress. Recent research suggests that neither the inclusion of modest amounts of clothing nor the clothing fabric alter thermoregulation or thermal comfort during exercise in warm conditions. In the cold, most reports do not support an effect of clothing fabric on thermoregulation; however, there are reports demonstrating an effect. Clothing construction does alter thermoregulation during and following exercise in the cold, where fishnet construction offers greater heat dissipation. Future research should include conditions that more closely mimic outdoor conditions, where high work rates, large airflow and high relative humidity can significantly impact thermoregulation.
The purpose of this article is to provide a brief overview of the effects of clothing on thermal balance during exercise. To ensure a basic understanding of the variables involved in thermoregulation, the factors affecting temperature balance will be discussed. The characteristics of clothing will then be discussed followed by the effects of clothing on thermoregulation in warm and cold environments. Lastly, recommendations on future research directions will be discussed. There are several topics on the interaction between clothing and thermoregulation that will not be discussed in this article. The reader is directed to excellent reviews on biophysical heat transfer,[1,2]influence of clothing during exercise/work on the biophysics of heat transfer,[3,4]and on the effect of protective clothing on temperature regulation during uncompensable heat.[5,6]