Because the temperature at the surface is often closely tied to the temperature underground, the concern for heat-related illnesses is just as important for workers in deep mines as for surface miners – and just like other safety processes, is best battled through prevention and knowledge of the condition.
Miners can feel the effects of heat stress in a multitude of ways, according to the Mine Safety and Health Administration (MSHA) and the National Institute for Occupational Safety and Health (NIOSH). Some of the specific factors that can lend themselves to the condition include high temperatures and humidity, hot mine machinery, coal prep plant dryers, welding operations, wall rock heat, and areas with poor ventilation, among others.
“[Additionally], you are more likely to suffer from heat stress if you are beginning a new job in a high heat environment, have had a heat-related illness before, use personal protective equipment (respirator, suit), take certain medication or are over 45 years old,” the agencies said.
“Physical fitness and health are [also] important personal factors in heat exposure. Workers with heart, circulatory, lung or skin disorders usually do not get along well in the heat … acclimatisation, or the process by which a worker gains increased tolerance to heat exposure gradually as work in that exposure continues, should be considered.”
Symptoms of the potentially lethal condition, for which some 150 workers have had lost-time incidents over the last half decade, are fairly easy to recognise. While an individual impairs safety at a mine because heat stress causes loss of concentration, some other effects are more sight-obvious: hot, dry, red or spotted skin, confusion, convulsions, loss of consciousness; additionally, the typical heat stress victim’s temperature is at or above 105F.
“Act fast to prevent brain damage or death,” the agencies cautioned. “Move the victim to a cool and shady area, loosen tight clothing, soak the clothing with water, and fan the head and upper body [and] get the person to a hospital right away.”
They also outlined the symptoms associated with heat exhaustion and heat cramps. The former is often marked by clammy moist skin, a pale or flushed face and a temperature that is normal to slightly high, and is caused by fluid and electrolyte loss.
Heat cramps, on the other hand, are involuntary contractions of muscles that are typically used to perform one’s work duties. Also related to electrolyte loss, they can usually be overcome with rest and fluid intake.
To help prevent all of these conditions, MSHA and NIOSH recommend miners prevent their occurrence by drinking lots of fluids – a cup every 20 minutes – and consuming electrolytes by drinking sports drinks or lightly salted water.
Additionally, clothing worn on the job should allow for evaporation of sweat, and breaks on one’s shift should be taken in a cool area.
MSHA also added that all workers who are exposed to hot areas should be examined by a physician prior to assignment: “Be sure that the physician is informed of the heat exposure so as to make the proper evaluation,” it said.
Acclimation is also important – the agency said management should allow new workers a five- to six-day period to become used to his or her surroundings, and during that time the workload and exposure time should be gradually increased.
