What causes chest discomfort in cold air around 15°F?

Chest Discomfort in Cold Air: Causes and Mechanisms

Chest discomfort when going out in cold air around 15°F is primarily caused by cold-induced bronchoconstriction from facial cooling and direct airway effects, along with increased cardiac workload from cold-induced vasoconstriction and tachycardia. 1, 2

Primary Mechanisms

Respiratory Causes (Most Common in Healthy Individuals)

Facial cooling triggers a reflex bronchoconstriction that affects both healthy people and those with underlying lung disease. 2 This occurs through:

• Cutaneous reflex mechanisms: Cooling of facial skin during cold exposure causes bronchoconstriction even during resting nasal breathing, with FEV1 decreasing approximately 9-10% in both healthy subjects and COPD patients 2
• Direct airway effects: Hyperventilation of cold air directly cools the central airways, triggering subclinical bronchial obstruction in healthy subjects and more pronounced bronchoconstriction in those with COPD or asthma 2, 3
• Mucosal vascular response: The tracheobronchial vasculature plays a major role in thermal balance of airways, and cold exposure disrupts this balance 3

Cardiac Causes (Important to Rule Out)

Cold exposure causes vasoconstriction and tachycardia, both resulting in elevated blood pressure and increased cardiac workload, which can unmask or worsen ischemic heart disease. 1

• In patients with pre-existing coronary artery disease: Cold exposure decreases coronary blood flow and can trigger coronary artery spasm, potentially causing angina or even myocardial infarction 1
• In healthy individuals: Coronary blood flow remains normal or slightly increased, and coronary spasm does not occur 1
• Epidemiologic correlation: Mortality from ischemic heart disease correlates with ambient temperature, with more deaths occurring during winter months 1, 4

When to Suspect Cardiac vs. Respiratory Origin

Features Suggesting Cardiac Ischemia (Requires Urgent Evaluation)

The American College of Cardiology describes angina as retrosternal chest discomfort characterized by pressure, tightness, heaviness, squeezing, or burning that builds gradually over minutes. 5 Key distinguishing features include:

• Quality: Pressure, squeezing, heaviness, or tightness rather than sharp pain 6
• Radiation: To left arm, neck, jaw, between shoulder blades, or wrist and fingers 5
• Duration: Typically 2-10 minutes, resolving within 5-10 minutes at rest 5
• Triggers: Worsens with exertion, walking uphill, against wind, or in cold weather 5
• Associated symptoms: Dyspnea, diaphoresis, nausea, vomiting, or lightheadedness 6

Features Suggesting Respiratory/Benign Origin

Pain that is sharp, fleeting, related to inspiration (pleuritic) or position, or shifting locations suggests a lower likelihood of ischemia. 6

• Point tenderness on chest wall examination renders ischemia less likely 6
• Relief with change in breathing pattern or body position 6
• Associated with cough or respiratory symptoms without cardiac features 6

Risk Stratification

High-Risk Features Requiring Immediate Cardiac Evaluation

The American College of Cardiology identifies age >65 years, women, diabetes mellitus, and known cardiovascular risk factors as high-risk features requiring immediate cardiac evaluation. 5

• Age >75 years with accompanying dyspnea, syncope, or acute delirium 7
• Known cardiovascular disease, hypertension, hyperlipidemia, smoking history, or family history 5
• Women, elderly, and diabetic patients may present with atypical symptoms including sharp or positional pain 8, 7

Low-Risk Features (Likely Benign)

• Young, healthy individuals without cardiac risk factors experiencing discomfort only with cold exposure 1, 2
• Symptoms resolve quickly upon returning to warm environment 2
• No associated cardiac symptoms (no diaphoresis, nausea, radiation) 6

Recommended Approach

For Patients With Cardiac Risk Factors

Call EMS immediately for anyone with chest pain or other signs of heart attack, rather than trying to transport the person to a healthcare facility yourself. 6

1. Obtain ECG within 10 minutes of presentation 8, 7
2. Measure cardiac troponin immediately 5, 7
3. Assess for acute coronary syndrome even if symptoms seem atypical 8
4. Consider aspirin (325 mg chewed) if signs suggest heart attack and no contraindications exist 6

For Low-Risk Individuals

Protective measures can prevent cold-induced respiratory symptoms:

• Wear protective clothing over the face (scarf or mask) in cold weather to warm inspired air 2
• Reduce exercise intensity in extreme cold to minimize hyperventilation of cold air 2, 3
• Pre-warm airways by breathing through nose rather than mouth when possible 2

Critical Pitfalls to Avoid

The American College of Cardiology advises against using nitroglycerin response as a diagnostic criterion, as esophageal spasm and other non-cardiac conditions also respond to nitroglycerin. 8

• Do not dismiss cardiac causes in women, elderly, or diabetic patients, as they frequently present with atypical symptoms 8
• Do not assume young age excludes cardiac disease if risk factors are present 5
• Do not delay evaluation if symptoms interrupt normal activity or are accompanied by cold sweats, nausea, vomiting, or lightheadedness 8
• Recognize that one-third of MI patients present without chest discomfort, and these patients have 2.2 times higher mortality 5