Exposure to natural cold and heat: Hypothermia and hyperthermia medicare claims, United States, 2004-2005

Objectives. We measured the burden of hypothermia-and hyperthermiarelated health care visits, identified risk factors, and determined the health care costs associated with environmental heat or cold exposure among Medicare beneficiaries. Methods. We obtained Medicare fee-for-service claims data of inpatient and outpatient health care visits for hypothermia and hyperthermia from 2004 to 2005. We examined the distribution and differences of visits by age, sex, race, geographic regions, and direct costs. We estimated rate ratios to determine risk factors. Results. Hyperthermia-related visits (n = 10 007) were more frequent than hypothermia-related visits (n = 8761) for both years. However, hypothermiarelated visits resulted in more deaths (359 vs 42), higher mortality rates (0.50 per 100 000 vs 0.06 per 100 000), higher inpatient rates (5.29 per 100 000 vs 1.76 per 100 000), longer hospital stays (median days = 4 vs 2), and higher total health care costs ($98 million vs $36 million). Conclusions. This study highlighted the magnitude of these preventable conditions among older adults and disabled persons and the burden on the Medicare system. These results can help target public education and preparedness activities for extreme weather events.