Climate Change and Winter Health: Implications for Physicians

Climate change is increasingly recognized as a major global health threat, with profound implications for seasonal disease patterns and patient outcomes. While much attention has focused on heat-related illnesses, the impact of climate change during winter months also merits clinical consideration. Despite rising global temperatures, climate change intensifies winter storms due to increased atmospheric moisture and wind speeds. This leads to unpredictable winters with more extreme weather events, variable precipitation, and disruptions in heating infrastructure. Cold weather is not merely a seasonal inconvenience but a complex environmental stressor requiring sustained attention.

Exposure to cold temperatures starts a systemic response. Initially, vasoconstriction occurs in the skin of the extremities to conserve body heat by driving oxygenated blood to support vital organs in the core. As cooling continues and heat is lost in the periphery via radiation, the temperature gradient between the core and the periphery increases, redistributing heat outward and reducing core temperatures. Muscle contractions, shivering, tachycardia, and tachypnea occur to generate heat. 

Cardiovascular and Respiratory Issues

Cardiovascular-cause mortality is the most identified health outcome associated with cold weather and is generally observed shortly after cold weather events. Cold temperatures are associated with increases in blood pressure, cholesterol, fibrinogen, and erythrocyte counts, which are risk factors for cardiovascular diseases such as myocardial infarction. Cold-induced stress can aggravate cardiovascular dysfunctions through the upregulation of cold shock proteins and inflammatory markers, significantly affecting mortality rates in colder climates. Physical and cognitive performance also occurs, highlighting the critical need for tailored nutritional and behavioral strategies in extreme environments. Each 1°C decrease in temperature increases cardiovascular mortality and morbidity, with the most pronounced effects on coronary heart disease, CHF, and aortic aneurysm/dissection.  

Cold temperatures can cause increased bronchospasm in COPD and asthma with severe asthma subtypes being affected more. People often spend more time indoors, which can lead to increased exposure to other indoor pollutants such as particulate matter and volatile organic compounds. Poor ventilation and the use of heating appliances can exacerbate indoor air quality issues, raising the risk of respiratory and cardiovascular problems. Power outages during severe winter weather drive increased use of alternative heating sources, raising the risk of carbon monoxide poisoning.

Thermal Injuries: Hypothermia and Frostbite

Severe cold increases the risk of hypothermia and frostbite, particularly among vulnerable populations. Hypothermia can present insidiously, especially in patients with impaired thermoregulation or those taking medications that affect heat conservation by causing impaired shivering response or altered vasoconstriction. Cardiac and cerebrovascular functions are most critically impaired as body temperatures fall below 35°C. Both physical and mental impairment are symptoms of exposure to severe cold. Cardiac irritability (such as arrhythmias, ventricular fibrillation, and cardiac arrest) and cerebral insults (including reduced cerebral blood flow and oxygen consumption) can occur after prolonged exposure to cold. Loss of consciousness, amnesic episodes, and ischemic stroke can result from decreased oxygen to the brain in extreme cold environments. Frostbite, often seen in extremities, may result in lasting tissue damage and increased risk of infection. 

Infectious Disease Risks

Climate change alters the seasonality of infectious diseases. Milder winters extend transmission periods for respiratory viruses and expand vector-borne diseases. Colder weather can promote crowding indoors, increasing exposure to airborne infections and norovirus. Colder air temperatures reduce nasal temperature and immune efficacy in the upper respiratory tract, facilitating viral replication, including influenza and coronaviruses. Additionally, frostbite and hypothermia can increase susceptibility to secondary infections due to impaired skin integrity and immune response.

Skin and Eye Problems

Low humidity and cold exposure increase rates of dry skin, eczema, and ocular surface disorders. 

Seasonal Mental Health Concerns

Seasonal affective disorder (SAD) and other mood disturbances have long been associated with winter. Climate change, through more frequent and severe winter storms, power outages, and isolation, can amplify psychological stress, anxiety, and depression. 

Trauma and Extreme Weather Events

Increasingly severe winter storms and ice accumulation contribute to higher rates of trauma, especially from falls on ice, motor vehicle accidents, and structural failures. Emergency preparedness and rapid intervention are essential to minimize morbidity and mortality. Health systems must adapt to surges in trauma cases and reduced access during extreme events.

Food Security and Nutrition

Disruptions in supply chains during winter, heightened by climate change, can limit access to fresh produce and essential nutrition, particularly among vulnerable populations. Poor nutrition impairs immune function and recovery from illness, compounding winter-related health risks.

Clinical Recommendations

• Advise patients with cardiovascular and respiratory disease on winter risks, medication management, and strategies to reduce exacerbations.
• Monitor for and promptly address hypothermia, frostbite, and other cold-related injuries, especially in at-risk populations.
• Monitor for medication effects that may alter thermoregulatory or cardiovascular responses during winter.
• Screen for infectious diseases with atypical seasonality and update vaccination strategies as needed.
• Assess for skin and eye conditions linked to winter exposures and provide guidance on prevention and treatment.
• Evaluate mental health for signs of SAD or climate-related stress; ensure patients have support networks.
• Educate on carbon monoxide safety and recognize medication side effects that may alter cold tolerance.
• Prepare for increased trauma during severe weather events and maintain emergency protocols.
• Support food security efforts and counsel patients on nutrition during winter.

REFERENCES

Achebak, H et al. Ambient temperature and risk of cardiovascular and respiratory adverse health outcomes: A nationwide cross-sectional study from Spain. European Journal of Preventive Cardiology, 2024. 31(9), 1080–1089. https://doi.org/10.1093/eurjpc/zwae021

American Red Cross Winter Safety Handout for Patients. https://www.redcross.org/content/dam/redcross/get-help/pdfs/winter-storm/EN_Winter-Storm-Preparedness-Checklist.pdf?srsltid=AfmBOooIOuxr7IxL0AiG9o49EpdmWF6dna36xk5HhnsHkX7uj_zxb-zN

Chen, Y.Het al. Effects of Exposure to Air Pollution and Cold Weather on Acute Myocardial Infarction Mortality. 2025;  Atmosphere, 16(4):469.

Conlona KC. Preventing cold-related morbidity and mortality in a changing climate. Maturitas. 2011; 69(3P):197-202.

Fan, J.-F et al. A systematic review and meta-analysis of cold exposure and  cardiovascular disease outcomes. Frontiers in Cardiovascular Medicine. https://doi.org/10.3389/fcvm.2023.1084611.

Gasparrini, Aet al. Mortality risk attributable to high and low ambient temperature: A multicountry observational study. 2021; The Lancet Planetary Health, 5(7), e437–e445.

Liu, Z., et al. Health effects of extreme low temperatures and cold waves on respiratory diseases. Biomedical and Environmental Sciences, 2024. 37(6), 682–685. https://doi.org/10.3967/bes2024.076

Mekjavic, IB et al.  Human performance and medical treatment during cold weather operations – synthesis of a symposium. International Journal of Circumpolar Health, 2023. https://doi.org/10.1080/22423982.2023.2246666 

Ni, W., et al. Cold weather exposure linked to increased risk of heart attacks. Journal of the American College of Cardiology. https://www.acc.org/About-ACC/Press-Releases/2024/09/02/10/31.

Otty-Anyanwu N. A Critical Analysis Of Cold Weather And Related Challenges To Human Health: Investigating The Control And Preventive Strategies. Modern Anthology In Education, Administration, Science And Technology. 2025; Isbn: 978-978-59921-6-8

Smid, D. J. Exploring the role of nutritional strategies in cold weather operations in military personnel. Frontiers in Physiology.2025:- https://doi.org/10.3389/fphys.2025.1539615