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Tuesday's temperature hit the upper 80s and low 90s across the Carolinas, giving us a preview of things to come this spring and summer. As average global temperatures rise with climate change, so do the number of dangerously high heat days. And with that comes health risks, especially for those with health problems and people who work outdoors or in hot environments.
A new analysis by Climate Central of federal weather data from 247 locations across the U.S. shows that most (232) have seen the annual number of risky heat days rise since 1970. Climate Central measured the number of days with temperatures above the "minimum mortality temperature" for each location. That means temperatures at which the statistical likelihood of death from heat stress begins to rise.
These places now average 21 more risky heat days per year than in 1970. In the Carolinas, the number of risky days is at or above average in many places:
- Raleigh-Durham, 40 more risky heat days since 1970 (that's one of the biggest increases in the nation, according to Climate Central)
- Charlotte, 28 days
- Asheville, 21 days
- Greensboro-Winston-Salem, 26 days
- Greenville, 31 days
- Columbia, S.C., 34 days
- Greenville-Spartanburg, S.C., 31 days
Coastal areas including Wilmington (16 days) and Charleston (19) also saw more risky heat days, though not more than the national average, according to Climate Central's analysis.
One other detail: High heat days are different for every location because of different climates and the way we acclimate to the temperature. As Climate Central notes: "A high of 80°F is considered sweltering hot in Fairbanks, Alaska, but a normal average in Miami. And 100°F is common in Phoenix, but treated as a dangerous heat advisory in New York City."
A risk for outdoor workers
Why is this a concern? Because extreme heat is the deadliest and fastest-rising of all weather-related risks, according to the National Oceanic and Atmospheric Administration (NOAA).
Uwe Reischl is a physician and professor in the School of Public and Population Health at Boise State University who studies extreme heat and work. "Normally, it takes about 10 days for a person to adjust to heat. We call that acclimatization," he told reporters on a farm work tour during last month's Society of Environmental Journalists conference in Boise, Idaho.
"In general, farmworkers who gradually are introduced to a hot environment do this without any problems," he said.
But as the number of extreme days grows and they come earlier in the year, that can lead to heat stress, especially among workers more at risk.
"If they're exposed to heat suddenly, it's more difficult. Age plays a role and younger people are able to acclimatize more easily than older people," he said.
The body reacts to heat stress by sweating. But outdoor workers often wear layers of clothing for protection from chemicals or the sun, and that can hinder their ability to adjust, Reischl said. He said outdoor workers need access to water.
"People have to drink a lot of water — maybe two or three times as much as they would normally do if they weren't in a hot environment. And that's sometimes complicated because, you know, if you're working on a construction site or in the field, water may not be readily available," he said.
Reischl also recommends training for employers and workers, and adjustments in work schedules.
"In order to compensate for the heat, the body tries to sweat as much as possible. We can reduce the amount of heat that's been generated by working slower or working less and resting," he said.
Workers also need better clothing, Reischl said. He actually helped develop a prototype outdoor work vest that both protects workers from the sun and keeps the body cool. Manufacturers balked at licensing the design, he said, because they couldn't make a profit at the $10 or $15 cost that workers could afford.
Rules evolving — slowly
Neither South Carolina nor North Carolina has heat stress standards for workers, although heat-related illnesses are a public health problem. The Natural Resources Defense Council estimated last year that 1.7 million workers in North Carolina and 819,000 in South Carolina work in industries at high risk for heat stress.
The N.C. Department of Health and Human Services reported 3,739 emergency department visits for heat-related illness in summer of 2022, among both workers and the general population. Of those, 71% were males, mostly between the ages of 25 and 44. The Piedmont region of central North Carolina (60%) and coastal region (30%) accounted for most hospital visits, while the Sandhills accounted for about 15%.
The state Department of Labor has a webpage devoted to the topic, with guidelines and educational materials, including a "hazard alert" about the dangers of heat and work.
The federal Occupational Safety & Health Administration is promoting heat safety and drafting rules for heat exposure. A handful of states have adopted heat stress exposure limits and other workplace standards designed to prevent illnesses and deaths among outdoor workers, according to the Natural Resources Defense Council.
For example, California's state code has a section on "Heat Illness Prevention in Outdoor Places of Employment." It requires, among other things, access to shade and water, training, daily reviews of heat procedures, and 10-minute breaks every two hours when the temperature tops 95 degrees.
Worker advocates would like to see a national standard. In the meantime, the Natural Resources Defense Council says California's rules can be a model for the rest of the country.
Energy efficiency bill update
The state Senate now has a bill that would block updates to North Carolina's building code and energy efficiency rules.
The bill passed the state House of Representatives last week and could come up in the Senate next week, according to its chief House sponsor, Republican state Rep. Mark Brody of Union County.
The proposed legislation would prevent the state Building Code Council from updating North Carolina's outdated rules for energy efficiency in new construction, such as windows, doors and heating/cooling systems.
Brody, a homebuilder, and the North Carolina Home Builders Association want to delay updates until 2026. Both say it would make houses too expensive.
But supporters of the changes say they would save homeowners money on their utility bills over the long term, especially as energy prices keep rising. They also say that failing to update the rules will cost the state millions of dollars in federal aid that's tied to the energy efficiency rules.