Discuss heat stress management. Explain the physiological hazard resulting from heat stress.
Ask question is related with ergonomics topic - Physical work Human energy consumption and heat stress management
Heat stress in ergonomics refers to the effect of environmental temperature on manual work. Though, excessive heat in the working environment can lead to heat stroke, it is important that we do not equate heat stress with just heat stroke. Heat stroke, is one of the medical problems that may result from excessive heat and is applicable to people at work or in any other situation. Heat stress on the other hand refers to problems of heat as well as cold and is focused on work related issues only.
The human body needs to maintain its temperature at a standard temperature oh 37 degrees centigrade, and has an internal mechanism called homeostasis. The stresses that act against the ability of body to maintain its standard temperature include environmental temperature as well as heat generated within the body. When the body does more work, it generates extra heat, which must be dissipated to the environment to maintain standard body temperature. The environmental temperature affect the rate at which the body dissipates heat to environment. When environmental temperature is too high, the body is not able to dissipate enough heat and temperature of the body rises above the standard. At still higher temperature the body may actually absorb heat from environment.
In environment that are too cold the body tends to loose heat too fast, and when the temperature is too high the body may loose more heat that generates under normal condition. Under such condition the body tries to generate extra heat just to keep its temperature at standard level. But again the body has limited capacity to do this, and when the temperature fall below certain level the body is unable to keep up with the heat loss, causing body temperature to fall below normal.
Thus both excessively high or low temperature interferes with working ability of people, and may cause damage to their health. Thus there is need to regulate the working environment within acceptable temperature range. When this is not possible, for example when working outdoors or when the work area cannot be separated from a process involving very high or very low temperature, to take preventive measures to reduce the impact of extreme temperature.
The most common method of adjusting to adjusting to temperature in work environment is to wear appropriate clothing suited to the environmental condition. Other methods of dealing with adverse environmental conditions include the following.
- Reduction of exposure time by giving periodic work breaks. More severe the environmental condition greater the frequency and duration of work breaks. Also where feasible, work in cold and hot environment may be alternated.
- Suitable sheds or other facilities should be provide to workmen to take rest during such work breaks,
- Fans may be provides in hot environment that blow air directly on operator to dissipate heat.
- Similarly in cold environment heat sources such as infra red lamps that can be directed at workers may be used.
- Frequently taking cold drinks and water in hot environments. Similarly, hot drinks should be taken in cold environment.
Heat stroke is the physiological hazard which occures when the management of the heat stress is improper. Besides environmental factors (temperature, humidity,radiant heat), heat stress is determined by the regimen of work and clothing requirements of the persons. It is important to have a routine in order to manage heat stress in every workplace. Such a possible routine it's described in the next three steps to be followed:
1) Evaluation of the heat stress which is done using a screening method established by the ACGIH (American Conference for Governmental Industrial Hygenists).
2) Screening and limitation of heat stress for the persons exposed to it. Pursuit of body temperature variations by using a thermometer.
3)Use of strategies of managing heat stress
The following signs are the mark of an occuring heat stress and they are requesting medical emergency care:
-confusion, irritability,disorientation, the loss of weight per shift is greater than the 1.5% from his body weight, the amount of sodium from his urinary, during a day, is less than the quantity of 50 milli-moles.
To avoid all these physiological hazards, the following measures could be applied:
-the time spent and worked in overheated environment should be shortened and followed by a time for resting in cool places;
-the amount of water intakes should be increased;
-the workload should be distributed;
-disseminating the informations about the symptoms of heat stress so that the workers to protect themselves;
-scheduling the jobs which require hot conditions during the cooler part of the day or maybe choosing a cooler season for performing these activities.