Time required to stabilize thermographic images at rest

Thermography for scientific research and practical purposes requires a series of procedures to obtain images that should be standardized; one of the most important is the time required for acclimatization in the controlled environment. Thus, the objective of this study was to identify the appropriate acclimatization time in rest to reach a thermal balance on young people skin. Forty-four subjects participated in the study, 18 men (22.3 +/- 3.1 years) and 26 women (21.7 +/- 2.5 years). Thermographic images were collected using a thermal imager (Fluke (R)), totaling 44 images over a period of 20 min. The skin temperature (T-SK) was measured at the point of examination which included the 0 min, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20. The body regions of interest (ROI) analyzed included the hands, forearms, arms, thighs, legs, chest and abdomen. We used the Friedman test with post hoc Dunn's in order to establish the time at rest required to obtain a T-SK balance and the Mann-Whitney test was used to compare age, BMI, body fat percentage and temperature variations between men and women, considering always a significance level of p < 0.05. Results showed that women had significantly higher temperature variations than men (p < 0.01) along the time. In men, only the body region of the abdomen obtained a significant variance (p < 0.05) on the analyzed period, both in the anterior and posterior part. In women, the anterior abdomen and thighs, and the posterior part of the hands, forearms and abdomen showed significant differences (p < 0.05). Based on our results, it can be concluded that the time in rest condition required reaching a T-SK balance in young men and women is variable, but for whole body analysis it is recommended at least 10 min for both sexes. (C) 2014 Elsevier B.V. All rights reserved.