How Hot Weather and Humidity Impact Your Heart and Blood Pressure and How to Stay Safe

If this summer is feeling a little hotter than usual, you’re not imagining it — according to CT Insider, 93% of New Haven’s summer has been warmer than average. While this added heat and humidity makes life a little uncomfortable, it’s also not helping your cardiovascular health. For starters, for every degree your internal temperature rises, your heart beats ten more times each minute.

At Internal Medicine of Greater New Haven, our skilled and experienced team of healthcare providers wants our patients to stay safe in this heat as summer is far from over. One of our concerns is people with cardiovascular issues, such as high blood pressure or heart disease, because high heat and humidity levels can increase the workload on your heart.

You should take steps to offset the impact of heat and humidity on your body even if you don't have a pre-existing cardiovascular issue. We still urge you to practice good preventive care. Let’s take a look.

The effects of heat and humidity on the human body

We already touched on the fact that high heat can raise your internal core temperature, which forces your heart to beat ten more times each minute for each degree. This statistic may not seem like a lot, but if you add it to the typical 60-100 beats per minute, we‘re looking at a 10-17% increase in your heart’s workload.

Another significant issue is a rise in blood pressure as your body circulates twice as much blood when it’s hot and humid and sends it toward the surface of your skin to keep your body cool internally. In excessive heat, your circulatory system becomes your body’s cooling system. As a result of this increase in circulation, your blood pressure rises.

The final danger is that, as your body tries to keep cool, it sheds water through sweat, which places you at risk for dehydration. Not only are you losing water, but also sodium and potassium, minerals your organs need to function.

It's critical to minimize the impact of summer temperatures on your body, especially when there is a spike in blood pressure from heat and humidity and the threat of dehydration.

Strategies for protecting your heart during high heat and humidity

Let’s review best practices when navigating this hotter world. Anytime the temps rise above 80 degrees and the humidity levels go above 70%, we recommend that you follow these strategies:

• Stay inside during the hottest times of day — usually between noon and 5pm
• Drink water throughout the day, especially before, during, and after activity — about one cup every 15-20 minutes
• Stay in the shade and wear hats and clothes that cover you up
• Avoid caffeine and alcohol, which can lead to dehydration
• Try not to overdo it in the heat, and take plenty of breaks

If, at any time, you feel chills, nausea, lightheadedness, muscle cramps, or excessive sweating (or no sweating), stop whatever you’re doing. These are signs of heat stroke; you need to get out of the heat and drink some water as soon as possible. You should also come to see us if your symptoms are moderate to severe.

If you have a pre-existing heart condition, such as high blood pressure, heart failure, or other heart disease, it’s simply best if you stay out of excessive heat altogether. So, on those high-alert days, stick to places that offer air conditioning and avoid going outside until the sun goes down.

If you have more questions about weathering the heat and humidity in New England and protecting your heart health, we invite you to schedule an appointment with one of our health care providers. We have offices in Cheshire, Guilford, Hamden, Milford, North Haven, Meriden, Wallingford, West Haven, and Stratford, Connecticut.