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

You may think summer is simply a time to relax, but for your heart, extreme temperatures can pose serious risks. If you’ve ever felt unusually fatigued, dizzy, or short of breath on a hot day, your cardiovascular system could be struggling to cope. 

Joel C. Milligan, MD, in Guntersville, Alabama, can help you monitor symptoms and understand how your body responds to heat. Whether you have existing heart concerns or just want to protect your health, knowing how heat and humidity affect your heart will help you enjoy the season with confidence. 

Why heat and humidity stress your heart 

When temperatures rise, your body works overtime to cool itself down. This means: 

• Blood vessels widen (dilate) to help release heat from your skin
• Your heart beats faster, pumping more blood to the surface 
• You sweat more, leading to fluid and electrolyte loss 

These changes can lead to lower blood pressure, dehydration, and strain on your heart. If you have conditions like heart disease, high blood pressure, or arrhythmia, this added stress can trigger symptoms or complications. 

How hot weather affects blood pressure 

Interestingly, hot weather can cause both low and high blood pressure, depending on your body’s response. Consider the following: 

Blood pressure drops 

Heat causes blood vessels to dilate, which can lower blood pressure and lead to dizziness, fainting, or fatigue. 

Blood pressure spikes 

Dehydration and strain on your heart can also lead to temporary spikes in blood pressure, especially in people with preexisting hypertension. 

Warning signs to watch for 

Hot weather can sneak up on you, especially when humidity is high. Watch for these signs that your heart may be under too much strain: 

• Dizziness or lightheadedness
• Rapid heartbeat
• Shortness of breath
• Fatigue or weakness
• Swelling in your ankles, legs, or feet 
• Chest discomfort or tightness (seek immediate medical help) 

How to protect your heart in hot weather 

With a few simple precautions, you can help your body handle the heat safely. Here’s how: 

Stay hydrated

Drink water regularly, even if you don’t feel thirsty. Electrolyte drinks can also help replace lost salts. 

Limit outdoor activity 

Avoid strenuous exercise during peak heat hours (typically 10 a.m. to 4 p.m.). 

Find shade or air conditioning 

Take frequent breaks indoors to let your body cool down. 

Dress for the weather 

Wear lightweight, loose-fitting clothes and a hat. 

Monitor your blood pressure 

If you have high or low blood pressure, check your readings more often during heat waves. 

Listen to your body 

If you feel unwell, rest and seek medical attention if needed. 

When to call us 

If you have heart disease, high blood pressure, or are on medications like diuretics or beta blockers, hot weather can affect your body’s ability to regulate temperature and hydration. Talk to Dr. Milligan about:

• Adjusting medications during hot months
• Recognizing early signs of dehydration or heat exhaustion 
• Whether additional heart monitoring is needed during summer 

In the end, hot weather can pose real risks to your heart and blood pressure. However, with the right precautions, you can enjoy the season safely. Stay cool, stay hydrated, and listen to your body. If you’re ready to learn more, call us at 256-582-5131 or use our online booking tool to schedule your appointment today.