## 4 Discussion
Additionally, statistical analysis showed no significant differences between temperatures in selected areas, both before and after PBC. Maintaining symmetry in the thermal response of players following exposure to extremely low temperatures confirms physiological regulation of blood flow, controlled by the autonomic nervous system that is assumed to be anatomically and histologically symmetrical. Post-exercise cryostimulation as a recovery strategy described in the literature refers to PBC and WBC. The differences between those two methods involve primarily the exclusion of the head in PBC treatment, as well as different ways to create cold, different device sizes, and mobility possibilities [31]. PBC devices seems to be very convenient during the competition season because of their mobility and portability. It requires less space; it is easier to contact participants during the procedure and to exit from a PBC cabin; it requires less maintenance than a WBC cabin. Currently, there are several technologies, models, and types of cryocabin construction for both WBC and PBC, but in most cases PBC is used with one-person cabin [10]. There is significant debate regarding the effectiveness of both modalities during athletic recovery. There are few examples in the literature of data describing the range of temperature changes in specific body surfaces that indicate the amount of heat take away from the body at a given time during PBC treatments, but it has been demonstrated that the thermal response after PBC is similar to the response after WBC [60; 61]. In our case, an innovative solution was used, i.e., a model of a multi-person cryocabin for PBC, which is important in team sports, giving the possibility of quick simultaneous impact on 4-5 players. Internal temperature sensors precisely regulate the temperature in the treatment cubic, which makes it possible to maintain it at a constant level among consecutive treatment sessions. The initial reaction of the skin after an extremely cold exposure is the release of noradrenaline and peripheral cutaneous vasoconstriction [62]. The sympathetic response occurs by lowering the temperature of the skin [18], skin blood flow [63], and muscle oxygenation [21]. In our research, thermal imaging showed that PBC treatment had the greatest effect on lowering the skin temperature of lower extremities, especially in the thigh area. However, as expected, the smallest temperature changes were recorded in the upper back and the upper chest. The main factor affecting such characteristics of temperature changes in the analyzed body surfaces is the specific structure of the open treatment cryochamber, which means that during the PBC procedure, the head, neck, and nape are located above the plane of the cooling agent effect. The cold temperature is obtained by spraying nitrogen (expanded nitrogen), blown directly into the treatment area. Moreover, the generated nitrogen vapors in the upper part of the cabin, at the border of contact with the air, lose their extremely low temperature by mixing with warm air, in contrast to the place of exposure of the lower body parts, where the most gas with the lowest treatment temperature accumulates [49]. Interestingly, [PERSON] et al. [64], in the study on the range of temperature changes in various areas of the body, observed a comparable variability of temperature reduction as a result of using WBC, i.e., in a closed cabin, where the exposure also included the head. Specifically, the cooling effect was stronger in the lower extremities, whereas in the trunk it was weaker, regardless of whether the treatment was carried out at \(-100\)\({}^{\circ}\)C or \(-140\)\({}^{\circ}\)C. Based on this report, it can be assumed that although during WBC in a closed system the patient's entire body is under the influence of the treatment, the temperature distribution in the cryochamber is uneven at individual heights. The magnitude of temperature changes obtained in our study was comparable to those described by [PERSON] et al. [65].