Hot Working Conditions
Hot working conditions can occur in a variety of different instances. For example:
- prolonged work under direct sunlight in summer (i.e.: asphalt paving or roofing in summer)
- wearable impermeable protective clothing when doing heavy work
- working in an enclosed area with a strong heat source, poor ventilation, and high humidity (i.e.: heavy equipment operators in an enclosed cab without sufficient ventilation)
Personal causal factors include: Age, weight, degree of physical fitness, degree of acclimatization, metabolism, dehydration, use of alcohol or drugs, and a variety of medical conditions such as hypertension all affect a person's sensitivity to heat. However, even the type of clothing worn must be considered. Prior heat injury predisposes an individual to additional injury.
Environmental factors include: ambient air temperature. Radiant heat, air movement, conduction, and relative humidity all affect an individual's response to heat.
Heat Stroke is the most serious heat related disorder and occurs when the body's temperature regulation fails and body temperature rises to critical levels. The condition is caused by a combination of highly variable factors, and its occurrence is difficult to predict. Heat stroke is a medical emergency that may result in death.
Heat Exhaustion signs and symptoms are headache, nausea, vertigo, weakness, thirst, and giddiness. Fortunately, this condition responds readily to prompt treatment. Heat exhaustion should not be dismissed lightly. Fainting or heat collapse is often associated with heat exhaustion.
Heat Cramps are usually caused by performing hard physical labor in a hot environment. These cramps have been attributed to an electrolyte imbalance caused by sweating. Cramps appear to be caused by the lack of water replenishment.
Heat Rashes are the most common problem in hot work environments where the skin is persistently wetted by unevaporated sweat. Prickly heat is manifested as red papules and usually appears in areas where the clothing is restrictive.
Heat Fatigue is often caused by a lack of acclimatization. A program of acclimatization and training for work in hot environments is advisable. The signs and symptoms of heat fatigue include impaired performance of skilled manual, mental, or vigilance jobs.
Cold Working Conditions
Cold working conditions can also cause problems for construction workers. For example, rain, snow, sleet and other wet and windy conditions can be unbearable for extended periods of time. Below are some other examples of cold conditions:
- cold air temperatures
- underground construction work
- working over water and falling in
Hypothermia occurs when body heat is lost faster than it can be replaced and the normal body temperature (98.6°F) drops to less than 95°F. Hypothermia is most likely at very cold temperatures, but it can occur even at cool temperatures (above 40°F), if a person becomes chilled from rain, sweat, or submersion in cold water.
Frostbite is an injury to the body that is caused by freezing of the skin and underlying tissues. The lower the temperature, the more quickly frostbite will occur. Frostbite typically affects the extremities, particularly the feet and hands. Amputation may be required in severe cases.
Trench Foot or immersion foot is caused by prolonged exposure to wet and cold temperatures. It can occur at temperatures as high as 60°F if the feet are constantly wet. Non-freezing injury occurs because wet feet lose heat 25-times faster than dry feet. To prevent heat loss, the body constricts the blood vessels to shut down circulation in the feet. The skin tissue begins to die because of a lack of oxygen and nutrients and due to the buildup of toxic products.
Knowledge Check Choose the best answer for the question.
2-5. Which of the following is a personal causal factor for heat stress?
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