The importance of using infrared thermography (IRT) to assess skin temperature (t) is increasing in clinical settings. Recently, its use has been increasing in sports and exercise medicine; however, no consensus guideline exists to address the methods for collecting data in such situations. The aim of this study was to develop a checklist for the collection of t using IRT in sports and exercise medicine. We carried out a Delphi study to set a checklist based on consensus agreement from leading experts in the field. Panelists (n = 24) representing the areas of sport science (n = 8; 33%), physiology (n = 7; 29%), physiotherapy (n = 3; 13%) and medicine (n = 6; 25%), from 13 different countries completed the Delphi process. An initial list of 16 points was proposed which was rated and commented on by panelists in three rounds of anonymous surveys following a standard Delphi procedure. The panel reached consensus on 15 items which encompassed the participants' demographic information, camera/room or environment setup and recording/analysis of t using IRT. The results of the Delphi produced the checklist entitled "Thermographic Imaging in Sports and Exercise Medicine (TISEM)" which is a proposal to standardize the collection and analysis of t data using IRT. It is intended that the TISEM can also be applied to evaluate bias in thermographic studies and to guide practitioners in the use of this technique.

Although the ability to sense skin wetness and humidity is critical for behavioral and autonomic adaptations, humans are not provided with specific skin receptors for sensing wetness. It has been proposed that we "learn" to perceive the wetness experienced when the skin is in contact with a wet surface or when sweat is produced through a multisensory integration of thermal and tactile inputs generated by the interaction between skin and moisture. However, the individual roles of thermal and tactile cues and how these are integrated peripherally and centrally by our nervous system is still poorly understood. Here we tested the hypothesis that the central integration of coldness and mechanosensation, as subserved by peripheral A-nerve afferents, might be the primary neural process underpinning human wetness sensitivity. During a quantitative sensory test, we found that individuals perceived warm-wet and neutral-wet stimuli as significantly less wet than cold-wet stimuli, although these were characterized by the same moisture content. Also, when cutaneous cold and tactile sensitivity was diminished by a selective reduction in the activity of A-nerve afferents, wetness perception was significantly reduced. Based on a concept of perceptual learning and Bayesian perceptual inference, we developed the first neurophysiological model of cutaneous wetness sensitivity centered on the multisensory integration of cold-sensitive and mechanosensitive skin afferents. Our results provide evidence for the existence of a specific information processing model that underpins the neural representation of a typical wet stimulus. These findings contribute to explaining how humans sense warm, neutral, and cold skin wetness.

Sensing skin wetness is linked to inputs arising from cutaneous cold-sensitive afferents. As thermosensitivity to cold varies significantly across the torso, we investigated whether similar regional differences in wetness perception exist. We also investigated the regional differences in thermal pleasantness and whether these sensory patterns are influenced by ambient temperature. Sixteen males (20 ± 2 yr) underwent a quantitative sensory test under thermo-neutral [air temperature (Tair) = 22°C; relative humidity (RH) = 50%] and warm conditions (Tair = 33°C; RH = 50%). Twelve regions of the torso were stimulated with a dry thermal probe (25 cm(2)) with a temperature of 15°C below local skin temperature (Tsk). Variations in Tsk, thermal, wetness, and pleasantness sensations were recorded. As a result of the same cold-dry stimulus, the skin-cooling response varied significantly by location (P = 0.003). The lateral chest showed the greatest cooling (-5 ± 0.4°C), whereas the lower back showed the smallest (-1.9 ± 0.4°C). Thermal sensations varied significantly by location and independently from regional variations in skin cooling with colder sensations reported on the lateral abdomen and lower back. Similarly, the frequency of perceived skin wetness was significantly greater on the lateral and lower back as opposed to the medial chest. Overall wetness perception was slightly higher under warm conditions. Significantly more unpleasant sensations were recorded when the lateral abdomen and lateral and lower back were stimulated. We conclude that humans present regional differences in skin wetness perception across the torso, with a pattern similar to the regional differences in thermosensitivity to cold. These findings indicate the presence of a heterogeneous distribution of cold-sensitive thermo-afferent information.

Thermoregulatory parameters during exercise are typically reported as global responses (Tcore and mean Tsk). In contrast, this study investigated regional skin temperatures (Tsk) over the body, in relation to regional skinfold thickness and regional perceptual responses for both sexes using a body-mapping approach. Nine males and nine females, of equivalent fitness, minimally clothed, ran for 40 minutes at 70% VO2max in a 10°C, 50% rh, 2.8 m.s-1 air velocity environment. Tsk was recorded by infrared thermography and processed to obtain population-averaged body maps. Rectal temperature and heart rate were monitored continuously throughout the running trial. Skinfold thickness was obtained for 24 sites and thermal sensation votes for 11 body regions. Males and females had similar rectal temperature, heart rate and regional sensations. Whole-body maps of Tsk highlighted the significantly lower regional Tsk for females (-1.6°C overall, p<0.01). However, the distribution of Tsk across the body was similar between sexes and this was not correlated with the distribution of skinfold thickness, except for the anterior torso. On the other hand, regional thermal sensation votes across the body were correlated with Tsk distribution during exercise (females: r = 0.61, males r = 0.73, p<0.05), but not at rest. Our thermographic results demonstrate the similar Tsk distribution for active males and females during submaximal running in the cold, though shifted to a lower mean value for females. This Tsk distribution was associated with regional sensations but not with local fat thickness. The described body-mapping approach can have implications in physiological modelling and clothing design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 and heart rate were monitored continuously throughout the running trial. Skinfold thickness was 9 obtained for 24 sites and thermal sensation votes for 11 body regions. 10Males and females had similar rectal temperature, heart rate and regional sensations. Whole-body 11 maps of T sk highlighted the significantly lower regional T sk for females (-1.6°C overall, p<0.01). 12However, the distribution of T sk across the body was similar between sexes and this was not correlated

Filingeri D, Fournet D, Hodder S, Havenith G. Tactile cues significantly modulate the perception of sweat-induced skin wetness independently of the level of physical skin wetness. J Neurophysiol 113: 3462-3473, 2015. First published April 15, 2015 doi:10.1152/jn.00141.2015.-Humans sense the wetness of a wet surface through the somatosensory integration of thermal and tactile inputs generated by the interaction between skin and moisture. However, little is known on how wetness is sensed when moisture is produced via sweating. We tested the hypothesis that, in the absence of skin cooling, intermittent tactile cues, as coded by low-threshold skin mechanoreceptors, modulate the perception of sweat-induced skin wetness, independently of the level of physical wetness. Ten males (22 yr old) performed an incremental exercise protocol during two trials designed to induce the same physical skin wetness but to induce lower (TIGHT-FIT) and higher (LOOSE-FIT) wetness perception. In the TIGHT-FIT, a tight-fitting clothing ensemble limited intermittent skin-sweat-clothing tactile interactions. In the LOOSE-FIT, a loose-fitting ensemble allowed free skin-sweat-clothing interactions. Heart rate, core and skin temperature, galvanic skin conductance (GSC), and physical (w body ) and perceived skin wetness were recorded. Exercise-induced sweat production and physical wetness increased significantly [GSC: 3.1 S, SD 0.3 to 18.8 S, SD 1.3, P Ͻ 0.01; w body : 0.26 no-dimension units (nd), SD 0.02, to 0.92 nd, SD 0.01, P Ͻ 0.01], with no differences between TIGHT-FIT and LOOSE-FIT (P Ͼ 0.05). However, the limited intermittent tactile inputs generated by the TIGHT-FIT ensemble reduced significantly whole-body and regional wetness perception (P Ͻ 0.01). This reduction was more pronounced when between 40 and 80% of the body was covered in sweat. We conclude that the central integration of intermittent mechanical interactions between skin, sweat, and clothing, as coded by low-threshold skin mechanoreceptors, significantly contributes to the ability to sense sweat-induced skin wetness.

We investigated the effects of mild evaporative cooling applied to the torso, before or during running in the heat. Nine male participants performed three trials: control-no cooling (CTR), pre-exercise cooling (PRE-COOL), and during-exercise cooling (COOL). Trials consisted of 10-min neutral exposure and 50-min heat exposure (30°C; 44% humidity), during which a 30-min running protocol (70% VO2max) was performed. An evaporative cooling t-shirt was worn before the heat exposure (PRE-COOL) or 15 min after the exercise was started (COOL). PRE-COOL significantly lowered local skin temperature (Tsk) (up to −5.3 ± 0.3°C) (P < 0.001), mean Tsk (up to −2 ± 0.1°C) (P < 0.001), sweat losses (−143 ± 40 g) (P = 0.002), and improved thermal comfort (P = 0.001). COOL suddenly lowered local Tsk (up to −3.8 ± 0.2°C) (P < 0.001), mean Tsk (up to −1 ± 0.1°C) (P < 0.001), heart rate (up to −11 ± 2 bpm) (P = 0.03), perceived exertion (P = 0.001), and improved thermal comfort (P = 0.001). We conclude that the mild evaporative cooling provided significant thermoregulatory benefits during exercise in the heat. However, the timing of application was critical in inducing different thermoregulatory responses. These findings provide novel insights on the thermoregulatory role of Tsk during exercise in the heat.

All 27 home-use tests sold in France in 1989 for the self-diagnosis of pregnancy were evaluated. The kits were first tested by qualified clinical chemistry technologists. Eleven kits with 100% specificity and 100% sensitivity were retained for the diagnostic study. Each of 638 laywomen was given a kit and asked to perform the assay with a coded urine specimen containing either no human chorionic gonadotropin (hCG) or an hCG concentration adjusted to the claimed detection limit (1 DL) or twice the detection limit (2 DL). After testing, each participant filled out a detailed questionnaire. The results showed a diagnostic specificity of 86-100% for 10 kits but a diagnostic sensitivity of 85-100% for only 5 kits at 2 DL and for only 2 at 1 DL. Among the 478 positive urine samples distributed, 230 were falsely interpreted as negative. The main explanation for such a high percentage of false-negative results was difficulty in understanding the explanatory leaflets accompanying the kits and hence in reading the results, regardless of the socioeconomic situation of the participant. We conclude that pregnancy home-use tests should be subjected to rigorous analytical controls and evaluated by a panel of potential users before being released on the market.

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