heat injury report

heat injury report

Heat Injury Prevention in the Workplace

1. Introduction

Workers who are exposed to extreme temperatures on the job can suffer heat-related injuries and illnesses. By taking preventive steps, employers can protect worker health and productivity. The current document revised the heat stress guideline in 2006 with respect to state of the art knowledge and collected experience of the effects of heat. It reflects the developments in relevant exposure limits for cold/hot, WEEL, BMGV, IBW, and assessment of heat strain NIOSH criteria in relation to occupational heat stress, and quantifies the effect of different levels of heat stress in a simple scheme. This guideline is meant to be used by persons who are involved in operations in hot environments either at home or abroad. This can be a situation where rapidly changing new demands can require action to the assessment of heat stress under a new aspect. While this guidance is not all encompassing, it brings to light many of the new issues that have arisen in relation to heat stress in the work environment. This guideline makes reference to heat stress, but the criteria and much of the information is the same for heat strain. This guideline is put forth in an attempt to identify the new issues that people are facing and how to assess if a safe level of heat stress is being approached. The guideline does not set forth new exposure limits for wet bulb globe temperature, but does use the NIOSH criteria of heat stress in a quantitative manner to compare and contrast the risk of different levels of heat stress at a given heat stress exposure. The student or practitioner can then use this information in an effort to avoid going over an acceptable level of risk. This guideline also serves to aid businesses in their efforts to assess and control the risk of heat stress to their employees and is an attempt to bring together scientists, workers, and employers to protect safety and health through education, research, and standards. This document provides help for both the scientist.

2. Understanding Heat-Related Injuries

Suggested: Do not consume any type of liquid when not feeling thirsty for approx 10-15 hours before physical activity, especially in the heat. This will ensure that aldosterone levels are high and maximum sodium stores are kept. This has no adverse effects apart from pre-race weight, but athletes should be properly educated about signs and symptoms of dehydration so as not to mistake it for weight loss during exercise.

EAH is well correlated with duration of activity and is more likely to occur in slower endurance events. New evidence now suggests that it is not necessarily the amount of water ingestion. High aldosterone levels normally cause sodium retention, however in heat stress aldosterone levels are at their lowest and so is the renal response to water ingestion. Fluid may then accumulate in the body rather than be excreted, often in excess of sweat rate, further lowering the blood sodium level. This will cause an osmotic imbalance where the brain cells, having lost water in order to keep body temperature constant, will swell. This swelling brain is the final cause of EAH symptoms and is what can be life threatening in severe cases.

The body’s regulation of temperature involves evaporation of sweat and it is important to note that fluids keep coming out of the skin even when there is little or no salt left. If excessive fluids are taken in at this time, or sports drinks and water are ingested, blood volume can increase and thus dilute the salt level even more. High fluid volume tends to stay in the intestinal area, this can sometimes be diverted from skin circulation and move to the muscle, which aids to dehydration. Ingestion of liquids has been linked to several cases of hyponatremia.

In order to set the stage for discussion and prevention of heat injury, we need an understanding of the mechanisms involved in causation. When the body is overheated, the brain sends signals to the skin to increase blood flow to the skin. This results in more blood being sent up from the heart. With the increase of blood flow to the skin, there is a decrease in flow to the muscles (75% of available blood flow goes to the muscle tissue). With a decrease in blood to muscles and exercising in the heat, muscle blood volume can decrease dramatically. This can lead to dilution of sodium levels in the blood and when salt losses are too high, muscle cramps or heat cramps can occur.

Symptoms and levels of heat injury

3. Implementing Safety Measures

Heat Acclimatization The bodies of unacclimatized workers will take up to 5-7 days to become accustomed to working in the heat. It is important that during this time the exposure to the heat is increased gradually so that the workers have time to adapt. Activities should be less strenuous and of shorter duration in the beginning, increasing in intensity and length over the course of 7-14 days (Hayward, Heat Acclimatization). This mode of training has been shown to greatly improve tolerance to working in the heat and reduce the amount of job-specific heat illness. Content of the slide here.

Administrative and Engineering Controls The primary focus of administrative and engineering controls is to provide work/rest regiments with the assistance of shade and frequent rest periods. The intent of such policies is to increase the number of rest breaks taken, and in doing so reduce the core body temperature of workers. Removal of the employees from the hot environment to a cooler one at the first sign of heat illness or excessive heat stress is a crucial protective measure and is discussed in the standard (OSHA, Heat Stress). An effective way to monitor the heat stress on the worksite is to develop and maintain a system of heat surveillance. This will give the employer an idea of where and when the hot spots are and enable them to avoid those areas during hot times of the day. An engineering control that is quite effective is the use of general ventilation or spot cooling to increase air movement and evaporative cooling on the skin. This can be achieved by utilizing fans and even high pressure ventilation systems (TreeNode, Engineering Controls).

Summary The implementation of a heat illness prevention program begins with an examination of the environmental and occupational risk factors for heat injury. The program should provide a series of procedures and policies that, when properly followed, will result in the prevention of heat illness. Specifically, the procedures and policies highlighted in this section are administrative and engineering controls, heat acclimatization, and an adequate medical surveillance system.

4. Training and Education

Accomplishing the best training usually means keeping the sessions short and holding many meetings to spread out the information. Providing training during downtime, such as during a tailgate safety meeting, is another effective means to ensure that all workers receive training. Use a method everyone can understand, like the tailgate training video available from the California Heat Illness Prevention Campaign. Always allow time for discussion and ask if the material is understood. An effective training tool can be found in the heat illness prevention “training guide,” which is available in English and Spanish.

Training is an important part of a heat-related illness prevention program. All employees need to be aware of the hazards of heat exposure and the employers’ policies to control the hazards. Supervisors and workers, particularly new workers, need to be trained on the prevention of heat-related illness. Training should be designed to cover the risk factors for heat illness, the importance of frequent water consumption, monitoring a person for heat illness, acclimatization, steps to take if someone has symptoms of heat illness, and appropriate first aid measures to take if someone has a heat illness.

5. Conclusion

Using the information that has been gathered, it can be stated that providing artificial cooling or improved ventilation is the most effective administrative control to prevent heat stress and injury. These controls are relatively inexpensive and have the added bonus of increasing worker productivity. The final alternative is to provide personal protective equipment and allow self-pacing of work. While this is the least effective and allows the greatest risk of heat stress, there may be circumstances where it is the only option. In this case, supervisors need to be trained to recognize the early signs of heat stress and make sure that medical help is available when needed.

In conclusion, the most effective way to avoid heat stress and subsequent heat injuries would be to engineer the workplace so that heat stress is removed or is at a tolerable level. This is not easy and can be expensive, but in the long run it will be cost effective for employers, and safe for employees. If this is not possible, administrative controls should be put in place to make sure that employees are not overexerting themselves in hot environments. This would involve job rotation, longer rest breaks, and easier duties during the hottest times of the day.

After presenting extensive information on the adverse effects of heat stress and heat injury, the readers would have little doubt regarding the possible risks involved in working under heat stress conditions. The single objective throughout the past five subtopics can be summed with the intention of emphasizing on the importance of the prevention of heat injuries in the workplace.