Health and Safety
The mildest negative effects of cooling are unpleasant thermal sensations and thermal discomfort. Further cooling may result in changes in muscles, circulation, respiration and hormones which decrease physical and mental performance.
Personal protective equipment (PPE)
• Cooling affects health at least by two mechanisms:
• Cooling has direct negative effects on blood pressure, respiratory tracts, stress hormones, muscles and joints. Frostbite and non-freezing cold injuries are also direct effects of cold.
• Cold induce a decrease in the work capacity which means that the workers have to do the same work with smaller resources. It causes higher stress in the work.
Blood pressure: Typical cold exposure in winter increases blood pressure by 20-60 mmHg. The older is the person, the higher is the increase. Face cooling alone is enough to increase blood pressure. Blood pressure is the highest when standing still or doing heavy work. Light exercise decreases blood pressure.
Respiration: Breathing cold air may constrict upper airways in sensitive persons. During heavy work, when breathing is intensive, the risk of airway constriction (“wheezing of breath”) is increased. Simple heat and moisture exchangers are helpful.
Stress hormones: If cold exposures cause repeatedly body cooling, stress hormone cortisol level may increase.
Muscles and joints: Muscle and joint pains are common in people working in cold.
Cold injuries: Frostbite can develop at any temperature below 0°C but the number of frostbite increases sharply below -25°C. Wind and metal contacts increase the risk of frostbite.
Any kind of sickness decreases cold tolerance.
Optimal safety is achieved at thermoneutral temperatures. Cooling of skin, muscles and nerves together with cold induced discomfort impairs work capacity and make workers more susceptible for accidents. Heavy protective garments which are absolutely necessary in cold, may impair sense of touch, vision and hearing and reduce the functional capacity, all of which may also increase the risk of accidents.
Winter environment with slippery surfaces, snow and ice as well as darkness may also increase the risk of accidents and injuries.