# Quantification of the Area of the Highest Temperature in
## 4 Discussion  
The total number of multi-colored-annotated pixels did not differ between foals and adult horses; thus, further analyses regarding comparisons of transformed infrared images are justified. Although these are still metabolically different groups, measured differences would provide new insights into the mechanisms of transition into developed homeothermym in adults. We have found higher surface temperatures in foals than in adult horses, confirming higher heat energy radiation associated with their higher metabolism related to growth and development, as well as smaller insulation [15, 41, 42, 43]. Smaller insulation also contributed to detection areas with the highest temperature values both in adults and foals [3, 21, 30]. Although data regarding surface temperature in foals are scarce, it is well known that other temperature measurements confirm a higher physiological temperature in foals than in adult horses [10, 40, 41]. Therefore, to the best of our knowledge, this is the first report comparing IRT features, both conventional Tmax and novel Area Tmax, between adult and young horses. While a different image processing method was used, most of the limitations primarily concern the complexity of acquiring reliable infrared images [3, 18, 19]. Variations in the background radiation were minimized by acquiring images in a closed stable with no surfaces exposed to sunlight. This ensured that the temperatures of the animals' surfaces were significantly higher than the background. The distance from the object not only affects the measured temperature values but also the homogeneity of the image. Along with distance, the influence of global radiation and atmospheric composition increases, especially within the first 20 m from the object [18, 19]. In this study, the average distance was 2 m, reducing signal disruption and maintaining image homogeneity. For foals, we focused on the acquisition of a similar number of pixels from each individual, following recommendations [3, 18, 19]. Coat thickness, which varies between foals and adults, affects the amount of radiated energy [2, 31]. We examined only the Polish Konik breed, which is quite uniform regarding hair coat, in an effort to minimize the influence of this variable. On the other hand, it is also crucial to assess the potential influence of stress and exertion immediately before image acquisition [2, 24, 29, 30]. An altered physiological state in the animal can obscure the effects of other variables and may not provide data about the resting metabolic maintenance rate; thus, we paid close attention to minimizing through adjustment to the daily routine. [PERSON] et al. (2011) have found Tmax in the horse body at rest to be 31.0 \(\pm\) 1.7 \({}^{\circ}\)C, which corresponded with our Tmax range in the examined adults [44]. Their value was measured in the head region, although the authors did not separate it into smaller areas. In the available literature, there is a lack of data regarding Tmax in the foal body at rest; however, the head region in foals is also suspected of being the warmest due to its high blood supply, relatively low insulation provided by the hair coat, and fat tissue [3, 30]. Similarly to the available data, we found the highest temperature in adults to be in the regions of the eye and nostrils; however, we included the temporal region as well [2]. In contrast to adult horses, we have found the highest temperature in foals to be only in the eye region. While this region is considered to be a thermographic marker of stress, we did not observe any stress signs in the animals during image acquisition. They exhibited normal behavior because the images were taken of untied, freely moving animals without physical contact. Moreover, the temperature of the foals' limbs differs less from the rest of the body compared to adults. This may show that foals are less capable of saving heat in this region due to conduction between arteries and veins [45].