Summer might have ended for students and parents across the country but the sweltering heat still lingers. The Dog Days of Summer are officially here - that time of the year when the mercury rises and the days tauntingly creep by. In ancient Greek times, the Dog Days were ushered in when the brightest star, Sirius, and its accompanying constellation, Canis Major, (Greater Dog) was highest in the sky. It was a time of year that brought extremes of drought, sudden thunderstorms, and a sense of mania likened to “mad dogs.”
Heat & Workplace Safety Requirements
Indeed, the heat across North America between late July through early September can be maddening. It can also be dangerous for those working in hot conditions. Furthermore, excessive heat can negatively impact productivity, increasing the likelihood of errors and mistakes due to fatigue and loss of concentration. Heat is a real concern for workplace safety and health; so much so that the National Institute for Occupational Safety and Health (NIOSH) updated the Criteria for a Recommended Standard: Occupational Exposure to Hot Environments (2016). In accordance with OSHA’s General Duty clause, the recommendations developed by NIOSH should be considered as the standard for working in hot environments. The report can be accessed at the following link.
For those unable to read through all 157 pages of this extensive report, a summary of key findings and notable facts is provided below.
Facts of Heat Related Illness & Injury
Heat related illness and injuries result from the body’s inability to maintain core body temperature within a range of 98.6 °F (37 °C) ± 1 °F. Maintaining this core temperature requires a constant exchange of heat between the body and environment through modes of convection, radiation, evaporation, and, less common, conduction.
Convective heat exchange is a function between the skin temperature, ambient air temperature, and the rate of air moving across the skin (velocity).
Radiative heat exchange is a function between skin temperature and the radiant temperature of solid surrounding surfaces.
Evaporative heat exchange (sweating) is a function between air movement (velocity) and the difference in water vapor pressure between ambient air and wetted skin at temperature.
Conduction is the direct transfer of heat between two mediums (solid, liquid, or gas). Jumping into a swimming pool on a hot day is one method of conductive heat exchange.
There are a multitude of factors that can cause heat exhaustion and associated illness.
Clothing can protect skin surfaces from sun radiation but it can interfere with heat exchange due to insulative and absorptive properties that raise overall core temperature.
A high heat index (normally caused by high humidity and lack of air movement) can render sweating ineffective.
Sweating can cause dehydration and electrolyte imbalances.
Ineffective heat exchange can cause circulatory disruption, endocrine imbalance, heat stroke (extremely severe), heat exhaustion, heat cramps, heat syncope (fainting), and heat rashes.
Preventing Heat Related Injury & Illness
There are many strategies to prevent heat related injury and illness. An essential starting point for preventing heat injury and illness is to help workers acquire some form of heat acclimation. This is individual-specific and may require different strategies and acclimation time for each worker. For employees new to a hot work environment, take special consideration and ensure medical monitoring is in place. Workers should be trained on heat related injury and illness as well as prevention strategies.
Primary strategies for mitigating heat injury and illness include but are not limited to:
Proper nutrition (including avoiding alcohol and replenishing electrolytes),
Physical fitness (those with excessive weight or cardiovascular issues may experience more heat related illnesses),
Proper clothing for the environment (allow for sweating, lightweight, etc), and
Cooling assistance in the form of HVAC, fans (air needs to be moved, not just cooled), ice packs, ice water, and shade.
Employees should be trained on the warning signs of heat stroke and heat exhaustion and know what to do if they suspect a coworker is suffering from heat related injury. More importantly, leadership and managers should continuously remind employees of the real dangers of heat and encourage proper breaks and self care. The loss in productivity due to heat related cognitive and physical fatigue or potential worker injury is much worse than slow, steady, and safe work in hot conditions.
"Progress Demands Change"