Cold-related illnesses: Cold weather can impact health
During the winter months in Minnesota, the temperature outside can be very cold. Exposure to cold temperatures, winter weather conditions, or cold water can have negative impacts on your health. When exposed to the cold, your body can lose heat faster than it can be produced. This can lead to cold-related illness or even death.
Cold-related illness includes many health problems such as hypothermia, frostbite, trench foot, or chilblains, that occur when the body becomes too cold. While these health problems are most likely at very cold temperatures, they can occur even at cool temperatures (above 40°F) if a person becomes cold from wind, rain, sweat, or cold water.
For more information on cold-related illness, winter weather, and climate change:
The Minnesota Department of Health (MDH) Climate & Health Program has tools and resources about climate change and health in Minnesota. Climate and Health Impacts-MDH
The National Institute for Occupational Safety and Health (NIOSH) has information and resources for workers who may experience cold stress. Working in the Cold-NIOSH
The Occupational Safety and Health Administration (OSHA) also has information available on winter weather preparation for businesses and workers. Winter Weather-OSHA
People exposed to cold temperatures, winter weather conditions, or cold water can experience acute illness that may result in visiting the Emergency Department (ED), hospitalization, or even death. Emergency Department (ED) visit data include patients that were treated in the ED and then either released or hospitalized for further care. ED visit data includes more patients than hospitalization data because in most cases people will visit the ED before becoming hospitalized.
Emergency department visit rate by year and sex
Emergency department visit rate by age and sex
Emergency department visit rate by sex
Cold-related emergency department visit rates in Minnesota annually by sex
The overall trend shows an increase in cold-related illness emergency department (ED) visits, although the number and rate varies from year to year. Overall, more males are seen in the ED for cold-related illness than females. In 2024, the ED visit rate for males was almost three times higher than for females.
Source: Minnesota Hospital Association. The break indicates a change in International Classification of Disease (ICD) coding from ICD-9 to ICD-10 on October 1st, 2015. Rates from 2000-2014 should not be compared to rates from 2015 onward.
Cold-related emergency department visit rates in Minnesota, by age and sex, 2019-2023
Males aged 15-34 had the highest rate of cold-related emergency department (ED) visits.
Source: Minnesota Hospital Association.
Cold-related emergency department visit rates in Minnesota by sex, 2019-2023
Males had the highest rate of cold-related emergency department (ED) visits.
Source: Minnesota Hospital Association.
Emergency department visit rates (County)
Cold-related illness emergency department visit rates by county, 2019-2023
The map of cold-related illness emergency department (ED) visits shows higher rates in Northern Minnesota.Overall, Minnesota 40 people per 100,000 visited the ED for cold-related illness.
Source: Minnesota Hospital Association. Rates based on counts less than or equal to 20 should be interpreted with caution; the rate maybe unstable because it can change dramatically with the addition or subtraction of one case. To protect an individual's privacy, hospitalization counts under 5 are suppressed if the underlying population is less than or equal to 100,000.
When exposed to the cold, your body can lose heat faster than it can be produced. This can lead to cold-related illness or even death. Cold-related illness includes many health problems such as hypothermia, frostbite, trench foot, or chilblains, that occur when the body becomes too cold.
Data Sources
Hospitalization and ED data are extracted from Minnesota Hospital Discharge Data (MNHDD), which is maintained by the Minnesota Hospital Association (MHA).
MHA data are periodically revised by the MHA to reflect more complete and accurate discharge information.
Mortality data are extracted from the MN Center for Health Statistics at the Minnesota Department of Health.
Data Questions
The numbers and rates of hospitalizations, emergency department (ED) visits, or deaths directly attributed to cold-related illness by year, gender, or age group in Minnesota.
If a segment of a population is at higher risk for hospitalization, a visit to the ED, or death resulting from cold exposure in Minnesota.
Allow for a better understanding of spatial and temporal trends of cold-related illness.
The data can be used to document changes in cold-related illness over time and identify vulnerable populations.
The data can be used to educate the public about the health effects from exposure to cold temperatures, winter weather conditions, or cold water.
The general public can use this information to better understand their risk of cold-related illness.
The maps can inform which Minnesota counties should be targeted for outreach and prevention efforts.
State and local partners can use these data for program planning and evaluation.
The total burden of cold-related illness in a population.
The number of people hospitalized or who visited the ED for cold-related illness. Personal identifiers are removed from the hospital discharge data before analysis, so we are unable to identify individuals who may receive care at more than one facility.
These data come from hospital records and death certificates and may not capture the full range of cold-related illness if exposure to excess cold is not explicitly documented.
This analysis does not capture the full extent of cold-related health outcomes because only cases where cold exposure was recorded as an underlying or contributing cause of illness or death were included.
Hospitalizations/ED visits
Minnesota residents who are hospitalized or visit the emergency department in the cold weather months (October-April) with a primary or other diagnosis of cold-related illness, defined as having any of the following ICD-9-CM codes: 991, E901.0, E901.8, E901.9, and E988.3 (excluding cases due to man-made cold exposure, ICD-9-CM code E901.1) and ICD-10-CM codes: X31, T68-69, or T33-34 (excluding cases due to man-made cold exposure, ICD-10-CM code W93).
The data source for hospitalizations and ED visits is the Minnesota Hospital Discharge Data. The Minnesota Hospital Discharge Data collects hospital discharge information from acute care hospitals submitting data to the Minnesota Hospital Association (MHA).
Hospitalizations include out-of-state hospitalizations of Minnesota residents in the nearby states of North Dakota, South Dakota, and Iowa. ED visits only include out-of-state hospitalizations of Minnesota residents after the year 2005.
Deaths
Minnesota residents deceased during the cold weather months (October-April) with ICD-10-CM codes X31, T68-69, or T33-34 (cold-related illness) listed as an underlying or contributing cause of death on the death certificate record (excluding intentional deaths and deaths due to man-made cold exposure, ICD-10-CM code W93).
Demographic and cause of death data are collected from death certificates. Minnesota Mortality Data is maintained by the Center for Health Statistics at MDH. data source for deaths is the Minnesota Mortality Data, which contains information on demographic and cause of death data collected from death certificates. Minnesota Mortality Data is maintained by the Center for Health Statistics at MDH. MN EPHT receives Minnesota Mortality data from the Injury and Violence Prevention Unit at MDH.
[Learn more about the ICD-10-CM codes from the International Statistical Classification of Diseases] (https://www.cdc.gov/nchs/icd/icd-10-cm/index.html)
ICD Codes Related to Cold Exposure
Code
Description
X31
Exposure to excessive cold of natural origin
T33
Superficial frostbite
T34
Frostbite with tissue necrosis
T68
Hypothermia
T69
Other effects of reduced temperature
Number
The number indicates the total number of hospitalizations, ED visits, or deaths.
To protect an individual's privacy, hospitalizations and ED visit counts from 1 to 5 are suppressed if the underlying population is less than or equal to 100,000.
Rate
A rate is a ratio between two measures with different units. In our analysis a rate is calculated using a numerator (the number of cold-related illness hospitalizations, ED visits, or deaths during a period of time) divided by a denominator (the number of people at risk in a population during the same period of time). This fraction is then multiplied by 100,000. Minnesota population estimates from the U.S. Census Bureau American Community Survey datasets are used to calculate a rate.
To protect an individual's privacy, rates based on hospitalization or ED visits counts from 1 to 5 are suppressed if the underlying population is less than or equal to 100,000.
Rates based on counts of 20 or less are flagged as unstable and should be interpreted with caution. These rates are unstable because they can change dramatically with the addition or subtraction of one case.
An age-adjusted rate is an overall summary measure that helps to control for age differences between populations. A weighted average, called the "direct method," is used to adjust for age. The U.S. 2000 standard population is used as the basis for weight calculations.
Age-adjusted rates are useful when comparing the rates of two population groups that have different age distributions.
For more information about the cold-related illness data and measures, contact MN Tracking at health.dataportal@state.mn.us.
