Summary
Heat and Fatigue related illness and injuries are on the increase in industrial work places. What follows is a series of suggested engineering controls, administrative practices and details on personal protective equipment that combine to help employers reduce the chance of illness and injury in relation to heat in the industrial workplace.
1. What is Heat Stress?
Heat stress is a series of conditions where the body is under stress from over heating. The human body has only very limited capacity to adjust to extremes of temperature and humidity. When these limits are exceeded heat cramps, heat rash, heat exhaustion, heat syncope (fainting) and heat stroke can occur. Heat stroke is the most serious of these conditions and can be fatal. As the levels of heat stress conditions rise, mental functions slow down, the ability to handle machinery is impaired and accident rates rise. The heat-affected worker can no longer be the best judge of his or her own condition.
2. Changes in workplace health & safety requirements relating to heat
Heat stress management has become a major issue in many industrial workplaces. Not only is it risk to the health and well being of the employee, it can be a major reason for increased accidents and lower productivity in the workplace.
Changes in both climatic conditions and industrial work place practices have impacted to create greater heat and fatigue related problems than ever before. For a start, it is hotter today than ever before. Long-term temperature trends in North America are consistent with global trends showing warming throughout the 20th century. According to a statement released by the World Meteorological Organization on 16th December 1999, the 1990`s had the highest global mean temperatures since instrumental records began being taken in the 1860`s.
Increasing safety standard regulatory requirements mean the amount of personal protective safety clothing and encapsulating suits required to be worn in the workplace has increased significantly. The more clothing a person wears the greater the heat load.
Many industries have now changed work patterns to longer ten or twelve hour shifts. Fatigue becomes an issue across the last quarter of a lengthy shift in hot or humid conditions. Conversely, some industries now face increased pressures of compressed work periods, where workloads increase significantly.
This is typified by planned maintenance shutdowns where a high level of work of a physically active nature must be completed within a compressed time period.
There is also now easier access in most industrial work places to drinks with high levels of caffeine and sugar and many foods available in the industrial workplace are high in sodium. All these factors combine to put the human body under stress and depending on the nature of the work these factors can have a serious impact on both the worker and the company if not managed correctly.
3. Communicating with employees
The establishment of an employee education program to build awareness of good work place practices relating to heat is an important step the employer can take to help reduce heat related problems and injuries. Recognition of the signs of the various types of heat stress conditions by fellow workers can help ensure the affected worker is treated immediately and therefore stop the deterioration of the workers health into a potentially life threatening situation.
The education process is best timed to precede the start of hotter or more humid weather conditions. This sends a clear signal to all employees to beware of heat problems, particularly if they are working in confined space or at remote locations.
The heat stress education program should cover the following topics
4. Causes, signs and symptoms of heat related illnesses
Heat Cramps
Symptom - painful spasms of the muscles, usually those muscles most used in performing the work. Occurs most often after vigorous exercise and profuse sweating.
Treatment: Resting in cool area with a fluid replacement often eases the cramps.
Heat Exhaustion
Symptom: Heavy sweating, weakness, dizziness, skin cold, pale and clammy. Pulse steady, normal temperature, possible fainting and vomiting.
Treatment -Get victim out of sun, lie victim down in cool environment, loosen clothes and provide water and electrolyte fluids.
Heat Syncope
Symptom: Could experience brief fainting, blurred vision, nauseated feeling, tired and may vomit.
Treatment: Lie down in a cool environment, provide fluids
Heat Stroke
Symptom: Skin is hot and dry, red face, high body temperature of around 106 degrees, possible unconsciousness.
Treatment: -Get victim to hospital immediately. Cool victim to reduce body temperature. Do not give fluids.
5. Fluid Replacement
Don’t wait for feelings of thirst before seeking fluids. Once you feel thirst coming, you’ve already dehydrated yourself. Dehydration occurs when the amount of water in your body falls below normal, leading to an imbalance of electrolytes. Other signs to tell you’re dehydrated include a reduced amount of urine that’s darker yellow, a dry mouth, weakness, muscles cramps and in more severe cases confusion and unconsciousness.
Loss of body fluid means what it says; loss of water plus its contents (electrolytes) from the body. Electrolytes can be simple inorganic salts of potassium, sodium, calcium, magnesium or complex organic molecules. These minerals are lost through perspiration or other forms of dehydration, particularly in heat stress situations. Intake of plain water replaces part of the loss; intake of an electrolyte drink replaces fluids plus the lost simple inorganic salts, all of which keep the body functioning properly. Within seconds of drinking a correctly balanced electrolyte replacement, the electrolytes are put back where they belong and energy is restored.
Getting workers to drink the recommended daily intake of water often proves difficult in many workplace situations.
Coffee and tea should be avoided as they act as a diuretic. A coffee drinker will have a significant loss of body fluid through increased urination.
While soft drinks, cordials and beverages are capable of providing carbohydrate food energy, they are largely empty calories. Soft drinks will make a person thirstier because of the extra solute entering the fluid environment surrounding the body cells.
Higher temperatures produce greater sweat losses and hence require a greater commitment to a fluid replacement program.
Independent tests in industry have shown that besides preventing dehydration, a regular fluid regime allowed subjects to work at a lower heart rate and at a lower relative workload. Psychologically, subjects reported feeling fresher, stronger more vigorous and more wide-awake when fluid was taken regularly.
It is important to have plenty of fluids available to employees in the area that the hot work is performed.
6. The Danger of Dehydration
Dehydration is a dangerous condition and every attempt must be made to avoid it. Work performance can be affected with a fluid deficit of as little as 1.5 to 2.0 liters (or 1% to 2% loss of body weight). Dehydration can cause - an increase in heart rate to do the same job, possible kidney damage over the long plus a lowered resistance to heat
7.Designing a fluid replacement program
An insufficient fluid intake results in a reduced work capacity and threatens both worker health and safety. For any work, which is physically demanding and performed over prolonged periods, muscles need large supplies of fuel to sustain work.
Drinking regularly before, during and after work is the most effective way to minimize the effects of dehydration during the working day, particularly during hotter days where fluid losses are greater due to increased sweat rates.
Ideally, the fluid selected should also contain energy (carbohydrates) to ensure a continuous supply of fuel is available to your working muscles in order to delay physical fatigue. For example, a study which reported that individuals who performed prolonged exercise improved their performance by: 6% if they drank water during exercise, 6% if they ate a high energy snack such as a banana and 12% if they drank a fluid and energy drink
CHECKLIST: Dehydration. The warning signs and what to do
Signs
Dry mouth, dark strong smelling urine, not going to the toilet often, flushed skin, muscle cramps, slower reactions, poor coordination, difficulty concentrating, exhaustion, headaches, irritability.
Prevention
Drink 2/3 cups of balanced fluid replacement before starting work, have small regular drinks throughout the day, avoid soft drinks, undiluted juice, tea, coffee, milk and alcohol before, during and immediately after work, have 2 cups of a balanced electrolyte replacement within 30 minutes of finishing work
Treatment for dehydration
Sit in a cool shady place, remove outer garments, have a large drink immediately, followed by regular small drinks until symptoms disappear, take care to maintain fluid intake throughout the rest of the day.
Recommendations
Avoid suffering the effects of dehydration by regularly drinking a fluid, which is low in sodium and contains no more than 8% energy, at a rate of 0.5 to 1 liter per hour, especially on hot summer days. Ensure that fluid is readily available close to where the work is performed.
Sqwincher, the Drink of Industry, is an electrolyte replacement drink scientifically formulated to safely replace mineral salts & replenish fluids at optimal absorption rates, which are depleted as a result of dehydration or through physical exertion. It prevents or reduces the severity of heat stress disorders and provides a supplemental source of energy plus quenches thirst.
Sqwincher has served industrial workers in Australia since 1999 and is the only fluid replacement drink especially formulated for the high heat of the industrial workplace. Sqwincher has proved very successful at reducing heat related problems and improving worker productivity.
Taste is an important factor; in ensuring workers drink the required amount of fluid. By providing a fluid with an acceptable taste and ensuring the fluid is close to where the hot work is performed, employers help ensure workers drink the required 5 to 8 liters of water daily. Because Sqwincher has a very palatable taste, plus is low in sodium, workers drink more when a Sqwincher fluid replacement program is uses as opposed to an ad hoc system, leaving it up to the workers to get a drink whenever they remember to do so. Y
Sqwincher offers a visual reminder to workers that fluid intake is readily at hand and it’s great tasting flavors encourages them to regularly drink. Independent tests prove workers drink more fluid under a Sqwincher program than when just water alone is offered. X
Sqwincher comes in a range of package types designed for the workplace.
These include liquid concentrates which are mixed in coolers, single serve sachets for portion control & portability and sugar free Qwik Stiks. There are even frozen Sqwincher Icy Poles available, which lower core body temperature.
It costs less to prevent a heat related illness or accident than it does to recover from one.
At less cost per liter than milk, Sqwincher is a proven, safe and economical way to ensure workers are hydrated and productive in heat.
CHECKLIST: Combating Fatigue
The signs of short-term fatigue
- Poor memory, loss of concentration, short attention span, carelessness and difficulty following instructions slow reaction time, irritability and weariness, reduced stress tolerance
The signs of chronic fatigue - all of the above plus
- Headaches, digestive problems, depression, mental instability
Prevention measures to reduce fatigue
- Always eat a big breakfast, eat high energy, easily digested foods such as filled rolls, yogurt, fruit and muesli bars during the day, cut down on fatty and sugary foods, aim for at least five hours or uninterrupted sleep each day, avoid alcohol, coffee, tea and other drinks containing caffeine for two hours before bed time, take time to relax away from work.
8. Personal Factors
Some aspects of an effective heat stress program are in the area of behavioral safety. Individuals with problems associated with weight management, illnesses, medications, diet or alcohol intake can be predisposed to heat stress related problems. Employees should be advised to avoid alcoholic beverages, get adequate sleep and maintain a low sodium diet and regular exercise program.
9. Heat Risk Assessment
The implementation of an effective heat stress reduction program requires a series of initiatives on the part of the company and the workers. A combination of engineering controls, administrative practices and the use of personal protective equipment are required to ensure a comprehensive program is in place. The major problem of heat stress, heat stroke, is caused by a combination of factors and the solution to avoiding heat stroke incidents is provided by a combination of initiatives by the employer and the employees.
10. Hazard Identification & Risk Factors
In addition to monitoring the air temperature, other factors, which must be considered, include high humidity, radiant heat, workload, type of clothing worn, lack of air movement and the acclimation levels of the individual.
A worker with a heavy workload, wearing an encapsulating protective suit, working in an area with high radiant heat and low air movement is in a very high-risk category. If that workers fluid intake is insufficient, if he has a high sodium diet, poor fitness levels or is not acclimatized to the environment then his chances of suffering a heat related problems are greatly increased.
11. Workload Assignment
High activity workloads increase an individual’s total heat load. Workload is described as light, moderate, heavy or very heavy. Light work could involve machine operators sitting or standing at equipment. Moderate work could entail walking about with moderate lifting or pushing. Heavy work would involve physical labor with a pick and shovel. Very heavy work would be defined as loading fuel in a blast furnace at a steel mill or foundry.
A good work practice is to help workers adjust to the heat by assigning a lighter workload and longer rest periods for the first five to seven days of intense heat.
12. Other recommended work place practices
The use of general ventilation and spot cooling at points of high heat production. Good airflow increases evaporation and cooling of the skin. Stagnant atmospheric conditions and poor airflow can induce heat related illnesses.
Alternating work and rest periods, with longer rest periods in a cooler area. Shorter, but frequent work-rest cycles are best. Schedule heavy work for cooler parts of the day.
Use appropriate protective clothing. Workers should change their clothing if it gets saturated. Lightweight, loose fitting and light colored clothing is best.
Encourage workers to drink plenty of fluids. One 180ml cup of Sqwincher every 15-20 minutes is recommended for workers in high-risk job roles. Avoid alcohol, coffee, tea cola, cordials and soft drinks, which contribute to dehydration.
Train workers to recognize and treat the signs of heat stress. Be sure all workers know who is trained to render first aid. Supervisors should also be able to detect early signs of heat related illnesses and permit workers to interrupt their work if they become uncomfortable.
Monitor temperatures, humidity and workers responses to heat at least hourly. Thermal environment & personal heat stress monitoring equipment is available to provide information to create a heat index. Personal heat stress monitors can store and display an individual’s temperature data and warns the user of temperatures which exceed a pre-set alarm level. Information is able to be down loaded to a PC or serial printer. Area heat stress monitors combine the effects of humidity and air velocity (natural wet bulb temperature), ambient air temperature, velocity and radiant energy (globe temperature) and air temperature (dry bulb) into a single index- (WBGT).
Y Source: Role of Carbohydrate-Electrolyte Fluid Replacement in the industrial environment: Human Performance Laboratory, University of Alabama, Tuscaloosa, AL, 1997.
¬ Kirk, P. 1997, Fluid and Energy for Forest Workers, Liro Forestry Institute, Rotorua, New Zealand.
X Source: Role of Carbohydrate-Electrolyte Fluid Replacement in the industrial environment: Human Performance Laboratory, University of Alabama, Tuscaloosa, AL, 1997.
