Despite large environmental variations, the human body maintains a tightly regulated core temperature. Effective thermoregulation must balance the interaction between skin surface, clothing and ambient air. Indices of thermal stress (wet bulb globe temperature, heat stress index, maximum evaporation rate, required evaporative rate and wind chill) provide valuable information concerning the heat exchange between the individual and the environment, and serve as protective guidelines while working in environmental extremes. The role of clothing, as an interactive barrier, greatly affects thermal balance. Clothing is varied according to prevailing environmental conditions, metabolic heat production, gender and age differences, fabric thermal properties, garment design and intended use. Models (static, dynamic and human) have investigated the biophysical transfer of heat between the skin surface area, clothing and ambient air. Additionally, the role of metabolic heat production during exercise can greatly influence tolerance to thermal stress during a variety of environmental conditions.

Clothing and exercise. I: Biophysics of heat transfer between the individual, clothing and environment

Temperature changes of selected body’s surfaces of handball players in the course of training estimated by thermovision, and the study of the impact of physiological and morphological factors on the skin temperature

https://www.degruyter.com/downloadpdf/j/humo.2012.13.issue-1/v10038-012-0002-9/v10038-012-0002-9.xml

The use of thermal imaging to evaluate body temperature changes of athletes during training and a study on the impact of physiological and morphological factors on skin temperature

Monochromatic and colored thermographies were used to visualize skin temperatures during exercise without involvement of sweating. Skin temperature began to fall immediately at the onset of exercise, remained low during exercise and rose rapidly after cessation of exercise. Increased work intensities produced a proportional fall in skin temperature and greater surface area of lowered temperature.

https://www.jstage.jst.go.jp/article/jjphysiol1950/31/5/31_5_757/_pdf

Fall in skin temperature during exercise observed by thermography.

The article presents the infrared (IR) thermovision diagnostic method as one of the tools for monitoring changes in an athletes' loading conditions during their training. The advantage of the method lies in its quantitative approach, fast analysis and the comparative studies involving the application of this method. All of the basic mechanisms of heat transfer to the skin's surface are presented, enabling a comprehension of the experimental results. In this article the results are presented as a temperature field distribution on a selected segment of skin and they change with time, depending on the integral parameters of an athlete's loading. Also examined were the characteristic changes in the temperature field which depend on an athlete's physical loading. In addition to a quality evaluation of the topological structures of the temperature field, time-related changes in locally averaged temperatures in a selected window were evaluated, as well as the pertinent time-dependent local temperature variations in individual training loading regimes. The results of the study indicate the rationality of applying the IR method for monitoring various types of loading on an athlete's muscle segments. This method may also be used as a comparative tool for establishing the efficiency of different means and methods in the training process.

Use of the thermovision method in sport training

The present study explores the dynamic changes of surface temperatures associated with peripheral vascular shifts during and following hand gripping, one-legged ergometric, and running exercise. An AGA 680 thermovision system, incorporating a Bolex 16-mm camera and displaying 10-colored isotherms on a slave monitor, generated synchronous infrared (IR) movies at 16 frame/s. Incremental increases in surface skin temperatures (Ts) were observed while gripping at 20, 50, and 80% of maximum with a peak rise of 1.7 degrees C. Thermographic recorded Ts changes during dynamic one-legged exercise were higher in the exercising leg than the resting leg. Surface temperatures dropped in both limbs following exercise. The advantages of the use of thermography during transient thermal states, as produced by dynamic exercise, is supported by comparative Ts data taken from thermograms and thermistors.

Bernauer Em

Papers

Temperature changes during exercise measured by thermography.