Atrial Fibrillation & Extreme Heat (Florida Edition)

Woman lying on couch sweating with tand on forehead holding paper fan

The Sunshine State boasts a subtropical climate that means hot and humid conditions for most of the year. During the summer, we often get temperatures over 90°F, and the combination of high temperatures and humidity can make it feel even hotter than it is.

These prolonged periods of excessively high temperatures can pose significant health risks to vulnerable populations such as the elderly, children, and individuals with pre-existing health conditions.

According to the American Heart Association, extreme heat can exacerbate existing cardiovascular conditions and even trigger new ones. Atrial fibrillation, or Afib, is among them. In this article, we’ll talk about the effects of Florida’s heat on cardiovascular health, specifically focusing on atrial fibrillation. By understanding the connection between heat and heart health, we can take measures to protect against heat-related cardiovascular issues.

What Is Atrial Fibrillation?

The heart comprises four chambers: the upper two (atria) and the lower two (ventricles). The atria act as the heart’s pacemaker and keep heartbeats in sync. Afib is a common heart rhythm disorder characterized by irregular heartbeats, which happen when the atria are out of sync with the ventricles. This results in ineffective blood pumping to and from the heart, which means less oxygenated blood reaching the rest of the body. Afib increases the risk of complications such as stroke, heart failure, and other heart-related problems. Treatment for Afib may include medication, lifestyle changes, cardiac catheter ablation procedures to restore normal heart rhythm, and managing underlying health conditions.

How Florida’s Heat Affects Cardiovascular Health

High temperatures strain the heart, which increases the risk of cardiovascular events, including Afib. One notable effect is that it increases the heart rate. As the body attempts to dissipate heat and maintain a stable internal temperature, the heart works harder to pump blood to the skin for cooling purposes. This increased demand on the heart can lead to a higher resting heart rate, potentially putting additional stress on the cardiovascular system.2

Heat exposure can also result in elevated blood pressure levels. The body’s response to heat includes peripheral vasodilation, where blood vessels near the skin widen to facilitate heat loss through sweating and increased blood flow to the skin’s surface. However, this vasodilation can decrease blood pressure in some individuals, prompting compensatory mechanisms such as increased heart rate and constriction of blood vessels elsewhere to maintain adequate blood flow to vital organs. These adjustments can contribute to temporary spikes in blood pressure, particularly in individuals with pre-existing hypertension.2

Increased heart rate and blood pressure stress the heart, particularly in individuals with underlying cardiovascular conditions. Prolonged exposure to high temperatures can worsen existing cardiac issues and increase the risk of heart attacks and arrhythmias.

How to Protect Your Heart When Out in the Heat

Stay Hydrated
The American Heart Association emphasizes the importance of staying hydrated, especially during hot weather, to prevent dehydration and maintain optimal cardiovascular function. Drinking plenty of water throughout the day helps regulate body temperature and supports heart health.

Avoid Overheating
Stay indoors during the hottest part of the day, use fans or air conditioning to cool indoor spaces, and wear light-colored, loose-fitting clothing made of breathable fabrics. Taking cool showers or baths and using cold compresses can help lower body temperature and provide relief from the heat.

Avoid Strenuous Activity
Strenuous physical activity during peak heat hours can increase the risk of heat-related illnesses and cardiovascular strain. To avoid overexertion, it’s important to schedule outdoor activities during cooler times of the day, such as early morning or late evening.

Exercise and being out and about are very important for continued health, but Florida’s hot and humid temperatures pose significant risks to cardiovascular health, particularly increasing the risk of Afib. It is very important to stay hydrated, keep cool, and avoid excess activity during periods of extreme heat. By prioritizing heart health and implementing preventive strategies, you can enjoy Florida’s warm climate without serious effects on cardiovascular health.


  1. Florida Department of Health. Health Effects of Summer Heat in Florida.; 2015.
  2. Chen H, Zhang X. Influences of Temperature and Humidity on Cardiovascular Disease among Adults 65 Years and Older in China. Frontiers in Public Health. 2023;10. doi:
  3. American Heart Association. 5 Ways to Keep Your Heart Safe in Extreme Heat. American Heart Association.
  4. Paul A, Alex R, Jacob JR, Yadav B. Effects of Heat Stroke on Surface ECG: a Study on Clinical Outcomes. Heart Asia. 2019;11(2):e011221. doi:
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