1. Introduction

Being warm-blooded creatures, humans can maintain a stable temperature of their bodies despite the large temperature fluctuations of the surrounded environment. The thermophysiological comfort is one of the aspects of the human comfort both indoors and outdoors. It is preconditioned by the functioning of the thermoregulatory system of the body and its reactions to the temperature of the surrounding air, the activity performed, and the used clothing insulation. Body's thermoregulation is very sophisticated and tries to maintain the temperature of the core body around 37°C while balancing between the heat, gained or produced, and the heat, released by the body to the surroundings.

According the definition in [1], cold is any environment, where people are exposed to a temperature below 15°C. The British standard BS7915 (1998) [2] determines that "cold environment" is the one with an air temperature below 12°C. People are working in a risky cold

distribution, and eproduction in any medium, provided the original work is properly cited.

environment, which can be natural (outdoor) or artificial (indoor) cold environment. It is the clothing only (in the past) and special protective clothing (at present) that is the only barrier between the human body and the cold environment. Clothing, activity, and proper management of the occupational activities help and maintain the thermophysiological comfort of people, working in the cold.

The purpose of this chapter is to present details about the human thermoregulatory system and the thermophysiological reactions of the body in a cold environment. Natural cold environment and artificial cold environment are compared to the light of their different effects on the occupational activities and management of the cold exposure. Cold-related injuries as part of the thermoregulatory reactions of the body and the risk from cold exposure are summarized. Clothing and hi-tech garments for protection from extreme temperatures are discussed. Practical advices and standards for the management of the occupational activities in the cold are presented.
