During the previous summer, the United States experienced its most scorching temperatures on record, coinciding with unprecedented peaks in heat-induced health crises in select areas.
Throughout the United States, a significant portion of visits to emergency departments stemming from heat-related issues—ranging from heatstroke and heat cramps to sunburns—occur within the warmer months, spanning from May to September. This trend typically reaches its zenith during July and August, as indicated by surveillance data compiled by the US Centers for Disease Control and Prevention.
Throughout the warm period last year, instances of heat-related ailments represented a 20% larger portion of visits to emergency departments compared to the preceding five seasons. Examination of data from numerous emergency departments nationwide reveals that in 2023, 180 out of every 100,000 total visits were attributed to heat-related illnesses, contrasting with 151 out of every 100,000 total visits between 2018 and 2022.
The perils associated with peak temperatures are escalating, evidenced by the surge in rates of emergency department visits due to heat exceeding previous peaks and surpassing other periods within the same warm season. In July and August of the previous year, CDC data indicates that there were over 300 heat-related emergencies per 100,000 total emergency department visits. This figure marks an increase of nearly 50% compared to the average peak rate from 2018 to 2022 and approximately three times higher than rates observed during other warm-season months in the same year. In preceding years, the risk during the pinnacle of heat was approximately twice that of other warm months within the same year.
The US Department of Health and Human Services defines a day as experiencing extreme heat if the temperature surpasses 95% of the average historical temperatures in that specific region. The CDC evaluated trends in heat-related emergency department visits against a comparable threshold.
In the year 2023, every corner of the United States witnessed at least one day when the frequency of visits to emergency departments due to heat-related issues soared to extreme levels, surpassing 95% of rates recorded between 2018 and 2022. Within a specific southern area, spanning Arkansas, Louisiana, New Mexico, Oklahoma, and Texas, instances of emergency department visits for heat-related ailments reached this extreme threshold for over a third of the warm season in 2023, including a stretch of 16 consecutive days. Across four southern regions encompassing 21 states, 2023 marked a record number of days with extreme rates of emergency department visits for heat-related illnesses.
In a report published last Thursday, CDC experts underscored that fatalities and illnesses linked to heat exposure remain an ongoing public health challenge, particularly as climate change leads to prolonged, hotter, and more frequent occurrences of extreme heat. They emphasized the importance of near real-time monitoring of weather conditions and adverse health outcomes, which can inform the timing of risk communication and the implementation of preventive measures in response to extreme heat events.
In August of the same year, the Office of Climate Change and Health Equity at the Department of Health and Human Services, in collaboration with the National Highway Traffic Safety Administration, introduced a dashboard leveraging data from the National EMS Information System. This dashboard tracks the rates of emergency medical services (EMS) responses to 911 calls related to heat-related illnesses and injuries. Updated on a weekly basis with a maximum lag of two weeks, the dashboard illustrates state and county standings relative to the national average, highlighting disparities based on age, race, gender, and urban-rural divide.
"Of all extreme weather phenomena, heat poses the gravest threat, and its impact worsens as global warming intensifies," remarked Dr. John Balbus, interim director of the HHS Office of Climate Change and Health Equity. "However, current data on heat-related fatalities fail to illuminate the precise locations where individuals become ill. This innovative dashboard enables us to pinpoint areas of greatest need, strategize for the future, and ultimately, save lives."
The CDC has leveraged data from participating health departments in the National Syndromic Surveillance Program's ESSENCE system to monitor trends in heat-related health issues. Notably, during June and August, heightened levels of heat-related emergency department visits prompted the agency to issue public health alerts, as outlined in Thursday's report.
It's worth noting that the new CDC analysis may underestimate the prevalence of heat-related illnesses, as it does not account for cases among individuals seeking treatment elsewhere. Moreover, the Covid-19 pandemic may have altered general healthcare utilization patterns, potentially affecting the reporting of such cases. Additionally, while broad regional analysis provides valuable insights, it may obscure more localized trends.
Recognizing regional patterns and disparities in emergency department visits for heat-related illnesses is crucial for informing the development and implementation of effective intervention strategies, as emphasized in the recent CDC report.
"The authors emphasized that the effective execution of heat mitigation measures is closely tied to social determinants of health," they noted, citing factors such as access to air conditioning, cooling facilities, and dependable power infrastructure.
Specific demographic groups are particularly vulnerable to the health hazards posed by heatwaves, including children, individuals with preexisting health conditions, expectant mothers, and outdoor laborers. In July, President Joe Biden called upon the Department of Labor to issue a "hazard alert" for heat and bolster enforcement efforts to safeguard workers from extreme heat exposure.
In a statement regarding the "hazard alert" proposal, the administration underscored the longstanding status of heat as the primary cause of weather-related fatalities in the United States. They highlighted the disproportionate impact of extreme heat on various occupational groups, including farmworkers, farmers, firefighters, and construction workers.
