Hot or Cold, Weather Plays a Big Role In Job Productivity
As this summer’s heat bakes construction workers to a sometimes record degree, many contractors assume hot weather is just another jobsite condition to be endured. But it is more than that: In addition to the health risks to workers, there is a definite decline in labor productivity in high temperatures. This is a factor to be considered in bidding and scheduling jobs and even settling delay and other claims.
In the U.S., there fortunately are cultural and legal reasons for employers to make sure workers in high-degree environments stay hydrated and wear proper attire. And workers themselves must take some responsibility for their own health in harsh conditions, just as they must for safety.
But the productivity issues don’t just stop at the jobsite. Even in industrial and office environments there are productivity declines as temperatures rise. Research in the U.K. and the U.S. indicates performance of industrial workers was less effective at 75.2° F than at 68° F. Office workers exposed to the same temperatures showed a reduction of up to 40% to 50%. Research also indicates heat stress has less effect on women.
There can be some precision in calculating the loss of productivity. One study uses a statistical polynominal regression analysis to establish a relationship between productivity and temperature. A set of equations reflecting the construction task and temperature predicts the change in productivity.
The flip side also is true, even though most firms don’t think about it during the summer. A paper prepared for the U.S. Army Cold Regions Research and Engineering Laboratory found that any manual work becomes extremely difficult below -40° F, regardless of a person’s experience and motivation, and construction equipment also is rarely operated. As temperatures rise, productivity climbs gradually until peak efficiency is reached at 50° F to 60° F for manual tasks and 40° F and above for equipment.
The effect of snowfall and wind velocity can be calculated using various equations. Manual tasks take 2.2 times longer than usual and equipment operations 1.3 times longer when the temperature is 20° F, the wind is 20 mph, and there is moderate snowfall.
These kinds of research are great tools for making construction operations more predictable, profitable and safe.