As we enter the middle of the year and the period of peak temperatures in the Northeastern U.S., many public employees face the prospect of having to work in high heat and humidity.  When the human body is no longer able to shed enough heat to remain healthy, heat-related illness can occur.   OSHA statistics indicate an average of 3,389 work-related heat injuries occurred in the U.S. during the period 2011-2020.¹ According to OSHA, “most outdoor fatalities, 50% to 70%, occur in the first few days of working in warm or hot environments because the body needs to build a tolerance to the heat gradually over time. The process of building tolerance is called heat acclimatization. Lack of acclimatization represents a major risk factor for fatal outcomes.”²

Thankfully, heat-related illness is preventable.

Many DVT members bring on seasonal help during the summer months. These new workers may not have spent time recently in warm or hot environments. They will need time to build tolerance (i.e., acclimatize or acclimate) to the heat. Accordingly, during their first few days working in warm or hot environments, these workers should be encouraged to:

• Consume adequate fluids (water and sport drinks)
• Work shorter shifts,
• Take more frequent breaks, and
• Know the warning signs and be able to quicky identify heat-related illness signs and symptoms.

A rapid response by fellow employees and/or supervisory personnel can make all the difference should an employee present with a heat-related illness. It is therefore a prudent survival skill to know the signs and symptoms of the most common heat-related illnesses – heat exhaustion and heat stroke.

Public employers should develop heat-related illness prevention plans that meet the requirements of the National Emphasis Plan that OSHA released in 2022 (click here for more information). There is a basic heat-related illness prevention plan contained in DVT’s sample Workplace Safety and Health Manual – Section 3.7.2. (Click here for a copy of this document). Supervisors and employees should be trained in how to recognize heat stress and plan work accordingly. OSHA and NIOSH both recommend a “Water, Rest, Shade” model that helps to promote working safely in the heat. Prudent precautions include drinking water the night before working in high heat and humidity.  While working, push fluids. Drink at least one cup (8 ounces) of water every 20 minutes while working, not just when thirsty. When the heat index is high, employees should take additional breaks. Workers should rest in a cool, shaded location when possible to shed excess heat. Pop-up gazebos or sun shelters are useful for creating shade when working in a fixed area that lacks natural shade or when there is no access to air-conditioned vehicles.

According to the CDC, younger workers under the age of 25, are twice as likely to be injured at work than older workers.² If your seasonal help is younger than 25, be sure to take extra care to ensure heat-related illness training is provided to those workers and their supervisors. More information on young workers and heat illness can be found here.

The U.S. Department of Labor offers a free to download Heat Safety Tool app that can help public employers to evaluate workplace environmental conditions and determine heat indexes quickly. (Click here to get the Heat Safety Tool app).  Another useful tool for employers is the National Institute for Occupational Safety and Health’s (NIOSH) reference document, Occupational Exposure to Heat and Hot Environments, that can be used to create heat-illness related prevention programs.

In summary, the proper heat-related illness prevention plan can reduce the risk of public employees experiencing heat-related illness. DVPLT and DVWCT members with questions on working safely in high heat and humidity environments should contact the Risk Control Department (215-706-0101) or email their lead risk control consultant.

Sources:

1. “Heat Injury and Illness Prevention in Outdoor and Indoor Work Settings Rulemaking.” Occupational Safety and Health Administration, U.S. Department of Labor, 30 Aug. 2024, osha.gov/heat-exposure/rulemaking#:~:text=Additionally%2C%20there%20were%2033%2C890%20estimated,year%20in%20that%20time%20period.

2. “Heat – Overview: Working in Outdoor and Indoor Heat Environments.” Occupational Safety and Health Administration, www.osha.gov/heat-exposure. Accessed 3 June 2025.

3. “Nonfatal Occupational Injuries to Younger Workers – United States, 2012–2018.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 3 Sept. 2020, cdc.gov/mmwr/volumes/69/wr/mm6935a3.htm?s_cid=mm6935a3_w.