As the season changes and temperatures begin to rise, we all need to understand the risks associated with excessive heat exposure. The human body has mechanisms to cool itself, but when these are overcome by heat energy coming into the body, heat injury is the result.
Understanding Heat Illness
Heat illness is often described in stages – for example, heat edema, heat exhaustion, heat stroke – but naming conventions vary and the underlying principle is that heat injury occurs along a spectrum spanning from mild to severe. Based on individual susceptibility, preventive measures taken, and environmental conditions, progression from mild to severe may occur slowly or very quickly. A person’s activity level in the heat is also a major factor, with higher levels of exertion leading to more rapid development of heat illness. Temperature, humidity, and being in direct sunlight versus shade all influence the amount of heat energy in our environment.
Recognizing Signs of Heat Illness
Symptoms of heat injury can include feeling tired or lightheaded, headache, almost or fully passing out, flushed skin, swelling of the limbs, and nausea and vomiting. The amount of sweating may seem excessive, decreased, or absent.
Personal Risk Factors for Heat Susceptibility
Susceptibility to heat illness varies based on many factors, including age, general health and physical fitness, use of certain medications, level of hydration, and one’s degree of “acclimatization.” Acclimatization refers to a process of gradually increasing non-injurious exposure to heat, which allows the body to become increasingly efficient with its cooling mechanisms. Lack of acclimatization is why anyone, regardless of individual susceptibility, is more likely to be harmed by heat at the beginning of the hotter times of year.
Heat Risks in Different Work Environments
Heat illness is not a concern for those working indoors in air-conditioned spaces, but for those working indoors without air conditioning, risk can be high even with door and window and other ventilation. Though there may be shade from the sun, temperatures indoors can rise to levels higher than outdoors, increasing the chance of heat illness of any stage. Last year, Cal/OSHA issued new recommendations and standards regarding the prevention of heat illness in indoor as well as outdoor situations.
Prevention and Emergency Response Strategies
Preventative measures include wearing appropriate clothing for the temperature and conditions, staying well-hydrated, pacing oneself in terms of activity and taking breaks. Also important is being able to get to shade and cooler conditions for routine breaks and especially when feeling overheated. Once heat illness symptoms start, it is imperative to stop work, get to the coolest location possible, increase hydration, and, if needed, to consider cooling measures such as applying ice or cool cloths to the skin. Applying these to the head and neck is the most practical, efficient way to cool down. Anyone failing to quickly improve with these measures requires urgent medical attention. Anyone who is unconscious, confused, too weak to stand up, or vomiting due to heat illness should be considered a medical emergency.
For more information about heat illness and prevention, check out the CDC’s site on the subject at: https://www.cdc.gov/niosh/heat-stress/about/illnesses.html
