Cold-Related Illness and Deaths in Wisconsin, 2013-2023

Despite the increased frequency and intensity of heat waves in the United States, cold-related illness and deaths continue to be important health risks, especially in Wisconsin where cold weather is prevalent. This analysis explores trends and characteristics of cold-related illness and deaths related to environmental exposures in the state from October 2013 through April 2023.

Wisconsin hospital discharge data and vital records were used to identify cases of cold-related illness and death that occurred during 2013-2023. We compared trends over time, correlations with temperature, and differences in demographic characteristics between clinical outcomes using linear models and chi-square tests.

We found an average rate of 13.6 emergency department visits per 100 000 population, 5.2 hospitalizations per 100 000 population, and 0.9 deaths per 100 000 population associated with cold-related illness during this period. The rate of death from cold-related illness has significantly increased since 2013 (R2 = 0.84). Cases had high rates of co-occurring chronic conditions, with 67.3% (n = 8110) of all cases having at least 1 comorbidity. American Indian and Black races had the highest rates of all 3 clinical outcomes due to cold-related illness.

Cold-related illness and deaths are prevalent in Wisconsin, especially among the American Indian and Black communities and in people with chronic conditions. Housing status should be noted in medical records and examination reports to help improve data about people experiencing homelessness. Clinicians should be prepared to see patients with cold-related illness, even on days without extremely cold temperatures.