National patterns, mechanisms, and severity of frostbite injuries in U.S. emergency departments: A 20-year analysis of NEISS data.

BACKGROUND

National patterns of frostbite injury and severity in the U.S. remain poorly characterized. We aimed to describe the epidemiology, mechanisms, and severity of frostbite injuries presenting to U.S. emergency departments (EDs).

METHODS

We analyzed 2005-2024 National Electronic Injury Surveillance System (NEISS) data. Cases were identified via combined diagnosis- and narrative-based searches. Weighted national estimates and logistic regression examined factors associated with serious emergency department disposition (admission, transfer, or observation), used as a pragmatic indicator of resource-intensive care.

RESULTS

Of 1096 identified cases (42,054 weighted), injuries peaked in January, with December-February accounting for 54.7%. Environmental cold (41.1%) and contact cold (36.6%) were primary mechanisms. Males comprised 61.6% of cases; the 18-34 age group was largest (28.1%). Overall, 11.3% of cases resulted in serious disposition. Higher odds of serious disposition were associated with male sex (OR 2.91, 95% CI 1.75-4.84), age ≥ 65 years (OR 7.91, 95% CI 3.62-17.3), and social exposure (OR 3.57, 95% CI 1.89-6.77). Contact injuries were associated with lower odds of serious disposition (OR 0.47, 95% CI 0.27-0.81).

CONCLUSIONS

Frostbite injuries in the United States are seasonal, mechanistically heterogeneous, and more likely to require serious emergency department disposition among older adults, males, and individuals with social exposure. These findings suggest that exposure burden and clinical severity follow different patterns and support prevention strategies that address both environmental risk and social vulnerability.