Hypothermia statistics vary by definition. The supplied studies measure clinically diagnosed accidental hypothermia, broader cold-related deaths, emergency visits, hospital admissions, or low temperatures among trauma patients.
Key Hypothermia Statistics
The following figures summarize measured findings across the supplied studies:
- In the United States, 40,079 deaths had cold recorded as an underlying or contributing cause during 1999–2022.
- U.S. cold-related age-adjusted mortality rose from 0.44 to 0.92 per 100,000 people between 1999 and 2022.
- U.S. adults aged 75 or older had a 2022 cold-related mortality rate of 4.23 per 100,000.
- In the United States in 2022, males had a cold-related mortality rate of 1.34 per 100,000, compared with 0.51 for females.
- American Indian or Alaska Native people had the highest listed U.S. 2022 rate, at 6.26 per 100,000.
- U.S. emergency departments had an estimated 15,574 hypothermia or other cold-related visits during 1995–2004.
- U.S. Medicare recorded 8,761 hypothermia-related visits, including 359 fatalities, in 2004–2005.
- Denmark recorded 5,242 adult hospital admissions for accidental hypothermia from 1996 through November 2016.
- Denmark’s mean annual accidental-hypothermia incidence was 4.4 per 100,000 inhabitants during 1996–2016.
- Danish mortality after accidental hypothermia was 11% within 7 days, 16% within 30 days and 27% within one year.
- In Japan during the 2018–2020 winter seasons, 73.4% of hospitalized accidental-hypothermia cases occurred indoors.
- Japanese registry patients had 24.5% overall 30-day mortality during the 2018–2020 winter seasons.
- In Japan, 43.0% of patients had mild, 35.2% moderate and 21.9% severe hypothermia.
- In U.S. trauma-center admissions in 2004, patients below 35°C had 25.5% mortality, compared with 3.0% at 35°C or higher.
- In British Columbia during 1998–2012, 45.9% of hypothermia deaths occurred in December, January or February.
- New Zealand’s hypothermia hospitalization incidence was 6.9 per 100,000 people per year during 1979–1986.
Contents
- Key Hypothermia Statistics
- U.S. Hypothermia Deaths and Long-Term Trends
- Hypothermia Statistics by Age, Sex, Race and Region
- Hypothermia Emergency Visits and Healthcare Burden
- Accidental Hypothermia Hospital Cohort Statistics
- Hypothermia Outcomes by Severity and Clinical Context
- Cold Exposure, Seasonality and Hypothermia Risk Factors
U.S. Hypothermia Deaths and Long-Term Trends
The U.S. mortality analysis for 1999–2022 used ICD-10 codes X31, T68 and T69. Its 40,079 deaths therefore represent broader cold-related mortality, not hypothermia-only deaths, and include underlying or contributing causes.
| U.S. mortality measure | Period | Finding |
|---|---|---|
| Cold-related deaths | 1999–2022 | 40,079 deaths |
| Age-adjusted mortality | 1999 | 0.44 per 100,000 |
| Age-adjusted mortality | 2022 | 0.92 per 100,000 |
| Overall trend | 1999–2022 | 109% increase; estimated 3.4% annual change |
| Recent trend | 2017–2022 | Estimated 12.1% annual increase |
The study reports a 109% increase in cold-related age-adjusted mortality from 1999 to 2022. Its Joinpoint estimates were 3.4% per year across the full period and 12.1% per year from 2017 to 2022; from 1999 to 2017, the estimated annual change was 1.0% and was not statistically significant, with a 95% confidence interval from −0.9% to 2.2%.
An older CDC analysis recorded 13,970 U.S. hypothermia deaths during 1979–1998, averaging 699 per year. Annual counts ranged from 420 to 1,024, and the age-adjusted death rate decreased significantly during that period (P<0.001).
Hypothermia-Related Deaths — Suffolk County, New York, and United States, 1979–1998
Hypothermia Statistics by Age, Sex, Race and Region
In 2022, adults aged 75 or older had a cold-related mortality rate of 4.23 per 100,000. The rate was 1.34 per 100,000 for males and 0.51 for females, while the estimated 1999–2022 annual percentage change was 3.0% for males and 3.1% for females.
| U.S. group or region | 2022 rate or trend |
|---|---|
| American Indian or Alaska Native people | 6.26 per 100,000 |
| Black people | 1.50 per 100,000 |
| Hispanic people | 0.51 per 100,000 |
| White people | 0.88 per 100,000 |
| Midwest | 1.41 per 100,000 |
| Midwest trend, 1999–2022 | 4.3% annual increase |
The racial and ethnic classifications come from death certificates and may be affected by small counts or misclassification. The four-region comparison is not a local weather-risk estimate.
British Columbia recorded 384 deaths listing hypothermia or excessive natural cold as an underlying or contributing cause during 1998–2012. The mean age was 52 years (SD 20.78), and men accounted for 73.2% of deaths.
Hypothermia as a cause of death in British Columbia, 1998-2012: a descriptive assessment
Hypothermia Emergency Visits and Healthcare Burden
The U.S. National Hospital Ambulatory Medical Care Survey estimated 15,574 emergency-department visits for hypothermia or other cold-related morbidity during 1995–2004. The 95% confidence interval was 9,103–22,045 visits, so the result is a survey estimate rather than a complete administrative count.
Hypothermia and other cold-related morbidity emergency department visits: United States, 1995-2004
Cold-related ED patients had a mean age of 45 years, compared with 36 years for other ED patients. They were 2.44 times as likely to be uninsured (95% CI 1.54–3.84), and their visits required critical-care transfer 6.73 times as often (95% CI 1.8–25.0).
Medicare recorded 8,761 hypothermia-related visits in 2004–2005, including 359 fatalities. Hypothermia-related mortality was 0.50 per 100,000 per year, inpatient visits were 5.29 per 100,000 per year, and outpatient visits were 6.93 per 100,000 per year among Medicare beneficiaries.
Hypothermia and other cold-related morbidity emergency department visits: United States, 1995-2004
These Medicare measures apply to beneficiaries and are not general-population rates.
Accidental Hypothermia Hospital Cohort Statistics
Hospital cohorts use narrower clinical definitions than the U.S. cold-related mortality study. Their denominators describe people who reached hospitals and met each study’s coding or temperature criteria.
| Country and period | Population measure | Main result |
|---|---|---|
| Denmark, 1996–November 2016 | Adult first-time admissions | 5,242 admissions |
| Denmark, 1996–2016 | Mean annual incidence | 4.4 per 100,000; annual range 2.9–6.4 |
| Japan, December 2018–February 2020 | Adults aged 18+ | 1,363 enrolled; 1,194 analyzed |
| Japan, 2018–2020 winter seasons | Analyzed patients | Median age 79 years (IQR 68–87) |
In Denmark, 43% of admissions had primary accidental hypothermia without recorded secondary diagnoses, 25% had accidental hypothermia as the primary diagnosis plus other secondary diagnoses, and 32% had another primary diagnosis with hypothermia recorded secondarily. Mortality was 11% within 7 days, 16% within 30 days and 27% within one year.
Accidental hypothermia in Denmark: A nationwide cohort study of incidence and outcomes
In Japan, 73.4% of cases occurred indoors and acute medical illness caused accidental hypothermia in 49.3% of registry patients. Cardiopulmonary arrest on hospital arrival occurred in 8.5%, while median ICU and hospital stays were 4 days (IQR 2–7) and 13 days (IQR 4–27); 30-day mortality was 24.5%.
Hypothermia Outcomes by Severity and Clinical Context
In the Japanese registry, 43.0% of patients had mild, 35.2% moderate and 21.9% severe hypothermia. The categories were based on emergency-department body temperature, and percentages may differ slightly from 100% because of rounding.
A meta-analysis of 18 observational studies found mortality odds 2.093 times higher below 36.0°C and 2.945 times higher below 35.0°C in critically ill adults. These pooled associations do not establish that temperature reduction causes death.
Inadvertent hypothermia and mortality in critically ill adults: Systematic review and meta-analysis
In the 2004 National Trauma Data Bank, 11,026 of 701,491 patients had admission temperatures below 35°C, and 802 had temperatures below 32°C. Trauma patients below 35°C had 25.5% mortality, compared with 3.0% at 35°C or higher; mortality reached approximately 39% at 32°C and remained approximately constant below that temperature, while 59.5% of patients below 32°C survived.
Admission temperature below 35°C had an adjusted mortality odds ratio of 1.54 (95% CI 1.40–1.71). These retrospective findings are conditional on reaching a trauma center and having a recorded temperature, and they remain influenced by injury severity and shock.
Injury-associated hypothermia: an analysis of the 2004 National Trauma Data Bank
Cold Exposure, Seasonality and Hypothermia Risk Factors
In British Columbia, 45.9% of hypothermia deaths during 1998–2012 occurred in December, January or February. Deaths occurred on days with a reported mean temperature of 0.56°C; alcohol was an additional cause in 40.1% of deaths, and other psychoactive substances were an additional cause in 22.7%.
Hypothermia as a cause of death in British Columbia, 1998-2012: a descriptive assessment
Historical national analyses reported the following associations:
- In the Republic of Ireland during 1979–1985, estimated hypothermia incidence doubled for each 5°C fall in ambient temperature.
Hypothermia and mortality and morbidity. An epidemiological analysis
* In the Republic of Ireland during 1979–1985, estimated hypothermia mortality doubled for each 4°C fall in ambient temperature.
Hypothermia and mortality and morbidity. An epidemiological analysis
* In New Zealand during 1979–1986, hypothermia hospitalization incidence was 6.9 per 100,000 people per year.
Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand
* New Zealand recorded 176 hypothermia deaths during 1977–1986, or 0.537 per 100,000 people per year.
Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand
* In New Zealand, 72.2% of fatalities were classified as domestic and 27.8% as non-residential.
Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand
* Among New Zealand domestic fatalities, 86.6% were aged 65 or older.
Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand
* Among New Zealand non-residential fatalities, 75.5% were aged 13–65, and 94.6% of that subgroup were male.
Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand
The Ireland relationships are historical ecological estimates and may not be linear outside the studied range. Country, climate, age structure and healthcare-system differences limit direct comparison, while death certificates and administrative records can undercount hypothermia.