Heat and Heart Attack Risk: Why Cardiologists Warn People to Be Careful
Headlines like “Heart attack surge: With this heat, you shouldn’t…” are often shared during hot weather, and there is a real reason doctors pay attention to heat exposure: extreme heat puts extra stress on the cardiovascular system.
When temperatures rise, the body works harder to cool itself. This can:
- Increase heart rate
- Cause blood vessels to widen
- Lead to sweating and fluid loss
- Lower blood pressure in some people
- Make the heart work harder to pump blood
For people with heart disease or risk factors, this extra strain may increase the chance of serious problems.
Things to avoid during extreme heat
1. Heavy outdoor activity during the hottest hours
- Try to exercise or do strenuous work in the early morning or evening.
2. Dehydration
- Not drinking enough fluids can make the blood thicker and increase strain on the heart.
- People with heart failure or kidney disease should follow their doctor’s fluid advice.
3. Sudden temperature changes
- Moving quickly between very hot outdoor conditions and very cold air conditioning may be uncomfortable for some people.
4. Ignoring warning symptoms
Seek emergency help for:
- Chest pressure, squeezing, or pain
- Pain spreading to the arm, jaw, neck, or back
- Shortness of breath
- Fainting or severe dizziness
- Cold sweats, nausea, or unusual weakness
People who should be extra cautious in hot weather
Risk is higher for people with:
- Heart disease
- High blood pressure
- Diabetes
- A history of stroke or heart attack
- Older age
- Certain medications that affect fluid balance (such as some diuretics)
Heat safety tips
- Drink fluids regularly unless your doctor has advised fluid restriction.
- Wear light, loose clothing.
- Stay in shaded or air-conditioned areas when possible.
- Check on older family members and neighbors during heat waves.
- Keep taking prescribed heart and blood pressure medicines unless your healthcare provider tells you otherwise.
