Sweltering heat and humidity, cooling off at Barton Springs, or sitting under a porch fan listening to Cicadas in the late afternoon, these are the trademarks of a typical Austin summer day. As idyllic as summer seems for most of us, each year, extreme heat and humid conditions affect thousands of outdoor workers causing a range of heat illness that can affect anyone at any age in any condition. And, with temperatures already reaching 100 degrees in early June, we may be looking at a record-breaking summer heat wave this year.
The UT Health Austin WorkLife Occupational Health and Injury Clinic works closely with employers and employees to help educate, advise and care for individuals who may be most at risk for heat-related conditions. As seen in the chart below many risk factors contribute to heat-related illness such as rhabdomyolysis, heat exhaustion, fainting and heat rash.
Common Heat-related Conditions
Rhabdomyolysis is a serious condition brought about by trauma or contact, which causes the breakdown of a person’s skeletal muscle that is then released into the bloodstream. Brought on by heat exhaustion or heat stroke and without prompt attention, this condition can lead to kidney failure or even death. Outdoor workers and athletes may experience rhabdomyolysis after working or working out in the heat for prolonged periods. Affected individuals may complain about muscle pain, cramping, swelling, weakness and decreased range of motion in their joints. Another sign of rhabdomyolysis is dark or tea-colored urine.
Heat exhaustion may precede heat stroke, a much more significant condition. With heat exhaustion, your body core temperature may rise to between 100 and 102 degrees. Common symptoms include a headache, nausea, vertigo, weakness, thirst, heavy sweating, irritability, and a decreased urine output.
Fainting or heat syncope can occur in workers who stand all day or rise suddenly from a seated position, causing a temporary drop in blood pressure. They may feel light-headed, dizzy and sometimes faint. Dehydration and lack of acclimation are the main causes of this condition.
Heat rash may appear if a worker’s clothing is too restrictive. Tight clothing traps sweat close to the skin blocking the sweat glands. Sweat is unable to evaporate causing a red rash to appear. The rash will appear bumpy and red, and give off a prickly or hot sensation. It is important to remove tight or restrictive clothing and let the skin cool and air out.
Dr. Edward Bernacki, Executive Director for UT Health Austin’s WorkLife clinic, says acclimating to the heat in the early days of summer is key to preventing heat-related illness. In a recent interview with KXAN, he explains how people usually need two weeks to acclimate to working in the heat. It is important to remember to build up your heat tolerance slowly, you should wear light, sun protective clothing, and make sure to hydrate regularly. Dr. Bernacki compares it to being on a sports team, he explains that football teams do not run out to practice in full pads on the first day, they start with shorts, shirts, a helmet, and participate in lighter, less intense practices with frequent water breaks. As the two weeks pass, coaches incrementally add more gear and a little more intensity to the workouts until athletes are able to fully gear up and practice at their highest level. He advocates for the same incremental build-up for those who work outside during the summer.
Mind the Humidity
Humidity is as important as high temperatures when planning outdoor activities or work. Yes, humidity can mean the difference in how quickly a person may recover from heat exposure. When relative humidity is 75%, you cannot count on sweating alone to cool your body. However, high humid conditions and heat close to 100 degrees make it difficult to cool a person down. It is very important to cool a person suffering from heat illness’ whole body as soon as possible on high humidity days. A pool of water is usually the fastest way to cool a body, but if you do not have access to a pool or lake, use water-cooled or cooling garments or wet towels to help bring down body temperature as well. In less humid conditions, it may be easier to cool someone down with cool compresses, water and get them to rest in a cool, shady location.
What can you do?
Dr. Bernacki emphasizes, “The time people really get into trouble is when we get that first strong heat wave. Be hyper-vigilant, although you always want to be vigilant, that’s when heat illness usually occurs because people just aren’t used to the heat and humidity.” He shares some advice for staying safe throughout the summer:
- Take time to acclimate to the heat. It usually takes at least two weeks – you cannot rush it.
- Dress lightly for the weather. Wear breathable materials like cotton that are lightweight.
- Take frequent water breaks - 8 ounces of water every 20 minutes –no less no more - no more because you can over hydrate. Thirst should always be the best indicator of your need for water.
- Limit work or play during the hottest part of the day; instead plan outside activities in the early morning or late afternoon.
- If you do work in the heat OSHA and The National Institute for Occupational Safety and Health (NIOSH) have developed a helpful Heat App to help quickly assess the heat index and read tips to keep you safe during the day. You can download it here for Apple and Android: OSHA/NIOSH Heat App.
For more information about the UT Health Austin WorkLife Occupational Health and Injury Clinic, call 512-495-5900 or visit uthealthaustin.org. The clinic is located on the 9th floor, 1601 Trinity St. Convenient parking is available in the attached Health Center Garage.
- Criteria for a Recommended Standard Occupational Exposure to Heat and Hot Environments DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health [Brudvig and Fitzgerald 2007; Khan 2009; Cervellin et al. 2010].