Public Health Preparedness for Extreme Heat Events

Abstract

Heat is a dangerous hazard that causes acute heat illness, chronic disease exacerbations, adverse pregnancy outcomes, and a range of injuries. Risks are highest during extreme heat events (EHEs), which challenge the capacity of health systems and other critical infrastructure. EHEs are becoming more frequent and severe, and climate change is driving an increasing proportion of heat-related mortality, necessitating more investment in health protection. Climate-resilient health systems are better positioned for EHEs, and EHE preparedness is a form of disaster risk reduction. Preparedness activities commonly take the form of heat action plans (HAPs), with many examples at various administrative scales. HAP activities can be divided into primary prevention, most important in the pre-event phase; secondary prevention, key to risk reduction early in an EHE; and tertiary prevention, important later in the event phase. After-action reports and other postevent evaluation activities are central to adaptive management of this climate-sensitive hazard. Expected final online publication date for the Annual Review of Public Health, Volume 44 is April 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Impacts of the 2021 heat dome on emergency department visits, hospitalizations, and health system operations in three hospitals in Seattle, Washington

“…Heat illness results when the natural thermoregulatory mechanisms are overwhelmed 3 . Beyond the spectrum of heat illness, exacerbations of cardiorespiratory disease, renal disease, and psychiatric illness have been observed 2 . Multiple medication classes, including diuretics and psychotropics, can impede thermoregulation in heat exposure 3 …”

“…Similar findings have been published elsewhere and indicate the impacts not only on patient volumes but on ED throughput and function during these events. As communities implement early warning systems and heat action plans for extreme heat events, hospital systems need to be similarly prepared for patient surges, staffing shortages, and disruptions in critical utilities and supplies 2,35–37 . As reported in a regional emergency medicine conference on local ED experiences during the 2021 EHE, shortages of ventilators were experienced due to the high volume of patients experiencing respiratory failure, and there was extensive coordination between facilities to load balance high acuity ambulance traffic to EDs experiencing less demand 38,39 .…”

“…As communities implement early warning systems and heat action plans for extreme heat events, hospital systems need to be similarly prepared for patient surges, staffing shortages, and disruptions in critical utilities and supplies. 2,[35][36][37] As reported in a regional emergency medicine conference on local ED experiences during the 2021 EHE, shortages of ventilators were experienced due to the high volume of patients experiencing respiratory failure, and there was extensive coordination between facilities to load balance high acuity ambulance traffic to EDs experiencing less demand. 38,39 As the world continues to warm under anthropogenic climate change, the rate of EHEs will increase disproportionately, and the need for additional preparedness is clear.…”

“…3 Beyond the spectrum of heat illness, exacerbations of cardiorespiratory disease, renal disease, and psychiatric illness have been observed. 2 Multiple medication classes, including diuretics and psychotropics, can impede thermoregulation in heat exposure. 3 The findings in this analysis are consistent with these known mechanisms of HRI and other evaluations of the same EHE.…”

“…These findings are consistent with previous literature documenting risk factors for HRI. 2,3 Beyond clinical risk factors for HRI, prior work has demonstrated socioeconomic and community-level risk factors. 2,3 A heat-mapping project from the City of Seattle and King County demonstrated inequitable heat exposure with higher temperatures, persisting for longer, in urbanized neighborhoods with less tree cover.…”