CBO examines how daily temperature changes affect emergency department visits, spending on those visits, and deaths among people enrolled in Medicare and how projected temperature changes caused by climate change affect those outcomes.
Summary
CBO finds that historically, the relationship between temperature and health outcomes varies by climate region. Cold days increase emergency department visits and spending in the coldest and hottest regions but reduce both outcomes in moderate climates. Hot days increase deaths in cold and moderate regions. Cold days increase deaths in hot regions.
Projected effects also differ across climate regions. Accounting for adaptation, hotter temperatures are projected to reduce ED visits and spending in cooler regions, increase both outcomes in regions with moderate climates, and increase ED visits but reduce spending in the hottest regions.
Overall, higher temperatures and expected adaptation are projected to reduce ED spending and deaths and increase ED visits. The reduction in ED spending is driven by two factors: Warmer regions will experience even fewer cold days, and colder regions are projected to reduce their vulnerability to hot days, likely through adaptations such as expanded access to air conditioning. The reduction in deaths is driven by warmer regions, which will experience fewer cold days and are projected to further adapt to hot days as their average climate gets hotter. ED visits are projected to increase even as ED spending decreases: as regions with hot climates adapt to higher temperatures, the composition of visits shifts toward lower-cost encounters.
CBO's analysis does not account for the costs of adaptation or the effects of climate change other than those on temperature.