Introduction:
A single physical exertion rapidly evokes cardiovascular changes. Owing to the body’s ability to maintain homeostasis, it is able to respond to increased metabolic demand.

Aim of the research:
The aim of this study was to assess the effect of a single physical exercise performed at low temperatures (–10°C) on changes in blood serum protein profile, and to compare the results with a control group that performed the same activity in atmospheric conditions of 18°C.

Material and methods:
The participants of the study were divided into two groups: Group 1 (study group, n = 15) ran in a thermoclimatic chamber at an air temperature of –10°C, and Group 2 (control, n = 15) ran outdoors at an air temperature of 18°C. In group 1, the subjects (n = 15) performed a 5-minute warm-up in standing position, which was carried out before entering the thermoclimatic chamber of the Laboratory of Technoclimatic and Working Machines (LBT&MR) of the Faculty of Mechanical Engineering at Krakow University of Technology (Poland), at an air temperature of –10°C, and then participated in a beep test endurance shuttle run conducted until exhaustion under the supervision of a trainer. In Group 2 (n = 15), the subjects performed the same test protocol, but outdoors, with an air temperature of 18°C.

Results:
Blood samples were collected from the subjects before entering the thermal climate chamber and after leaving it (fasting, from the antecubital vein, volume 5 ml, into tubes) by a qualified nurse. The blood samples were analysed in the Diagnostyka S.A. laboratory in Krakow, Poland for protein electrophoresis.

Conclusions:
Prevailing temperature conditions during physical exercise had no substantial influence on the changes in analysed the blood parameters. An exception was 1-globulin [%], in this instance, a substantial impact of the experimental factor (air temperature –10°C) was shown, indicating that the increase in 1-globulin in low temperatures is primarily relative, associated with haemoconcentration rather than an actual increase in protein synthesis.