A Healthy Way Working Outdoor

Working environment has a fundamental effect on our health and well being. We spent 8 to 12 hours a day working for 5 to 7 days in a week. For those who spent working outdoor knows there’s a certain limit for us to be able to work properly, safely while keeping our health in check.

I’m well aware of the fact since I have been working as a field supervisor and a consultant for three years. My line of work insists me to travel to various places in Indonesia and I spent most of my working time outdoors.

From my experience working in Riau-Indonesia, where I’ve spent approximately 5-8 months going back and forth from there to Jakarta and also a year in Kalimantan. Working in very hot weather has physiological and psychological effects on workers. Hancher DE, Abd-Elkhalek HA on their research “The effect of hot weather on construction labor productivity and costs” have described that; working in very hot weather reduces workers productivity, and increases their irritability and loss of their enthusiasm for their work. Also, working in hot and humid environment, workers tend to store heat in body and result in imbalance of electrolyte and heat stroke because of the difficulty in evaporative heat loss even if the air temperature is not too high. In addition, decline of excitability of nerve and muscle, lack of concentration and decrease of accuracy rate can lead to the lack of work enthusiasm, the fall of productivity and the increase of accident rate.

Just for the record, the average temperature in Riau according to provincial Meteorology and Geophysics Agency (BMG) is 33.6 degrees Celsius, but reached as high as 36 degrees Celsius. While in Kalimantan, the average temperature is not as high, averagely 32 degrees Celsius, yet still after working outdoor for a while you could feel the effect from the hot air starting to kick in.

From Jing Zhao, Neng Zhu, and Shilei Lu research on “Productivity model in hot and humid environment based on heat tolerance time analysis”, living environment above 35 degrees Celsius or working environment above 32 degrees Celsius can be considered as high temperature environment, and environment whose relative humidity above 60% can be considered as high humidity environment. A higher relative humidity affects the perceived indoor air quality and thus affects thermal comfort.

The way temperature and humidity affect our physiologic and psychological aspect of workers is explained in the journal as follow; while working in hot and humid environment, the physiological indices were influenced greatly: heart rate could accelerate for about 20 min; mouth temperature could increase 1 degrees Celsius rapidly for about 20 min, when the mouth temperature came to 38.5 to 39 degrees Celsius, workers often felt they couldn’t work on and abnormal status of body such as naupathia, weakness or swirl would appear, which indicated that the human heat tolerance limit came; low blood pressure could decrease immediately within 20 min of the beginning of working. Human body sweated greatly to maintain the balance of body heat by sweat evaporation when they are exposed to long term hot environment. However, when the environment has a high humidity, the less sweat came and the shorter heat tolerance time is. It was calculated that when water loss rate per unit time reaches 0.02% 0.03%, human body came to the tolerance limit.

We should take note on the symptoms that often experienced by workers as they work out door. To know the limit of ourselves will keep us healthy and fit for a days work. Our reaction to the changes of weather temperature is also affected by our own fitness. If we stay healthy and fit, we’ll have longer heat tolerance time.

Heat tolerance time means the working period lasted from beginning to the time when human body heat tolerance extreme came. While, heat tolerance extreme containing both objective and subjective meaning means that the physiological indices of workers working in hot and humid environment come to a dangerous value or some heat stress disorder symptoms appear, such as vertigo, nausea, etc. From the research, when mouth temperature came to 38.5 degrees Celsius, or heart rate came to 165 bpm, or water loss rate came to 1% or some heat stress disorder symptoms appeared, workers were required to stop working and that time was considered to be the heat tolerance time.

Indeed, some jobs do require us to have an extra amount of time working outdoor. There’s no escape from that. What’s most important is what the healthiest way to work outdoor is?

According to the adaptive comfort standard (ACS) (ASHRAE Inc. ASHRAE Standard 55 thermal environmental conditions for human occupancy), the parameters of a comfortable environment were; an environment with temperature of 26 degrees Celsius, with relative humidity 60%. However, if the desired environment is not available then, according to Lind and Bass (Optimal exposure time for development of WHO. Symposium on temperature acclimation on acclimatization to heat), the best working time in hot and humid environment is 100 min every day. In hot and humid environment, the sweating quantity may be 6 to 8 l in one day. When water loss rate is more than 1.5 to 2%, productivity can be fall down; while when water loss rate more than 5%, heat harmfulness may happen. Therefore, when working in hot and humid environment, water should be supplemented every 15 to 20 min and the water temperature should be 10 to 15 degrees Celsius.

So, when you are working out door, remember to carry a bottle of water with you; fresh and pure water is healthier. Nowadays, there are many energy drinks or ion charged drinks, most of them use artificial sweeteners and other chemicals that would eventually have a bad effect on your health. Rest in the shade, it helps. The fresh air from trees helps juveniles you’re hot and weary body.