With summer upon the Northern Hemisphere, the first heat waves have already caused disruptions. Excessive heat watches have been issued for southwestern US states and southern UK. While the range of temperatures are vastly different in both areas (43 C in the US compared to 33 C in the UK), it’s important to keep in mind that individuals react differently to temperature. It’s also crucial to understand the context of heat waves. While temperatures of 38-40 C may be common in many areas, individuals from the UK, for example, are not accustomed to such temperatures and may experience significant symptoms in temperatures as low as 30 C.
Hot, humid weather conditions can quickly become dangerous, particularly for workers or anyone outdoors for long periods of time. Heat-related illness can develop quickly and become a severe, emergency medical event. Additionally, hot weather exposure generally is accompanied by excessive sun exposure. Excessive sun exposure can also lead to injury or illness. Everyone, especially outdoor workers, should take steps to protect themselves from the heat and lengthy sun exposure, to reduce the risk of illness or injury.
How to Protect Yourself from the Heat
Individuals should avoid exposure to extreme heat, intense sun, and high humidity whenever possible. However, if exposure is unavoidable, especially during work, there are a number of steps workers can take to reduce their risk of heat-related illness or injury. In addition to the general precautions listed above, workers should try to gradually build up to heavy work throughout the day with the heaviest work scheduled during the coolest parts of the day. Employees should take more breaks, preferably in the shade or a cool area, during extreme heat and humidity conditions. Outdoor workers should be particularly vigilant about water consumption by drinking water frequently (approximately one cup every 15-20 minutes) and ensuring they do not become thirsty. Outdoor workers should also be made aware that protective clothing or personal protective equipment may increase the risk of heat stress.
For employers with employees who work outdoors, there are many recommendations that can ease the risk of heat stress for employees. Employers should try to schedule maintenance and repair work during cooler months, and schedule particularly hot jobs for cooler parts of the day. Adjust work schedules to help acclimatize workers to hot conditions by exposing them for progressively longer periods to hot work environments. If possible, reduce the physical demands of workers, and use relief work or assign extra workers for physically demanding jobs. Employers should provide cool water or liquids, rest periods with water breaks, and cool areas for use during those break periods. Further, employers should provide heat stress training, and monitor workers who are at risk of heat stress.
Travelers and outdoor workers often face increased risk of overexposure to the sun, which can have serious health effects. UVA rays are present throughout the day, are the most significant cause of premature aging, and can contribute to skin cancer. UVB rays are most intense from 1000 to 1600, and are also most responsible for sunburn and skin cancer. UVC rays are filtered by the earth’s ozone layer and generally do not reach the surface. Increased exposure to UV radiation occurs nearer the equator, during summer months, at higher elevations, and between 1000 and 1600. Reflection from snow, sand, and water also increases exposure.
Symptoms of sunburn appear 3-5 hours after overexposure, worsen over the next 24-36 hours, and resolve in 3-5 days. Serious burns are painful, and the skin may become tender, swollen, and blistered. These symptoms may be accompanied by fever, headache, itching, and malaise. Skin peeling can occur 3-8 days after severe overexposure. Overexposure can also cause red, dry, painful eyes.
It is also important to remember that many common medications can cause photosensitivity reactions, which increase the risk of severe sunburn. Such medications include acetazolamide, which is part of a variety of treatment regimens; amiodarone for irregular heart beat; antibiotics such as fluoroquinolones, sulfonamides, and tetracyclines (especially doxycycline – a common antimalarial medication – and demeclocycline); furosemide for congestive heart failure; nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and naproxen; phenothiazine-based anti-psychotics; sulfonylurea-based treatments for type 2 diabetes; thiazide diuretics; and voriconazole antifungals. Individuals taking one or more of these medications – especially those with a history of photosensitivity – should take increased precautions to avoid overexposure or severe sunburn.
In order to avoid heat-related illnesses it is crucial to protect yourself from heat and sun exposure. When high temperatures are expected, ensure you minimize exposure to the sun and drink enough water to reduce the risk of illness or injury. In addition, make sure you follow warnings provided by your local government. Please see the Health Intelligence Team’s Sun and Heat Health Concerns Information Sheet for an overview of risks, symptoms, and prevention strategies.