7 Ways to Protect Your Heart and Blood Pressure During a Heatwave

As summer temperatures rise, your body's effort to cool down forces your heart to work much harder than usual. The impact of extreme heat on the heart—especially when combined with widening blood vessels and fluid loss from sweating—can trigger blood pressure fluctuations and pose life-threatening risks. According to warnings from Cardiology Specialist Asst. Prof. Hüseyin ÖZDİL at BHT CLINIC İstanbul Tema Hastanesi, taking simple yet effective precautions for heart health during hot weather can be truly lifesaving. To help your cardiovascular system get through this challenging season unscathed, you need to read your body's signals correctly and make a few strategic changes to your daily habits.

• To lower body temperature in hot weather, blood vessels expand, which can lead to sudden drops in blood pressure.
• If the fluids and minerals lost through sweating are not replaced, the heart's workload increases significantly.
• Being out in the sun, especially between 11:00 and 16:00, carries a high risk for heart patients.
• Those taking blood pressure and diuretic medications may need to adjust their dosages during the summer months under a doctor's supervision.
• In cases of chest pain, severe shortness of breath, or sudden fainting, you should seek medical help without delay.

How Does Extreme Heat Affect the Heart?

The human body is programmed to keep its core temperature steady at around 37 degrees Celsius. When the air temperature rises, the brain's temperature regulation centre kicks in, causing the capillaries near the skin to dilate. As the vessels widen, blood is directed towards the skin, and body heat is released through sweating. However, this natural cooling mechanism requires the heart to pump two to four times more blood than usual.

To fill the expanding vessels and keep blood pressure stable, the heart muscle increases its beats per minute. At the same time, heavy sweating flushes vital minerals like water, sodium, and potassium out of the body. When the fluid volume of the blood decreases, the blood thickens, and its tendency to clot increases. While a healthy heart can tolerate this extra burden, in individuals with blocked arteries or heart failure, this situation can pave the way for chest pain, rhythm disturbances, and even heart attacks.

Who is Most at Risk?

Although extreme heat affects everyone, the danger is much more pronounced for certain groups. The answer to what heart patients should look out for in summer starts with accurately identifying their risk profile. Elderly individuals, particularly those aged 65 and over, are at the top of the list because their sense of thirst weakens and the body's temperature regulation capacity declines.

Patients with heart failure struggle to meet the increased demand for blood because their heart's pumping power is already compromised. For those with coronary artery disease, thickened blood can trigger clot formation in areas with stents or plaque. Furthermore, hypertension patients are highly vulnerable to sudden drops in blood pressure, partly due to the effects of their medications. Overweight individuals, diabetics, and those with kidney dysfunction are also among the risk groups that feel the brunt of heatwaves the most.

1. Adopt a "Smart Hydration" Strategy

Waiting until you feel thirsty is a sign that your body is already dehydrated and cellular stress has begun. For the heart to pump blood comfortably and maintain blood fluidity, the fluid volume within the vessels must be kept stable. Drinking at least 2.5 to 3 litres of water a day is the first rule of protecting your heart in the summer. Rather than drinking large amounts of water all at once, sipping it slowly and frequently throughout the day improves absorption.

Tea, coffee, fizzy drinks, and energy drinks are no substitute for water. On the contrary, the caffeine they contain acts as a diuretic, causing the body to lose even more fluid. When you consume these types of beverages, you should always drink an extra glass of water alongside them to balance the lost fluid. For more comprehensive information on proper water consumption, you can review our Water Consumption in Hot Weather and Dehydration Prevention guide.

2. Review Your Medication Doses with Your Doctor

Because blood vessels expand and fluid is lost through sweating in the summer, blood pressure naturally tends to drop. A drop in blood pressure during the summer is a critical issue, especially for patients undergoing hypertension treatment. The doses of blood pressure medications or diuretics used to balance blood pressure in the winter may be too strong for the body in the summer. This can lead to blackouts when standing up, dizziness, and sudden fainting.

You should consult your doctor and request that your medications be readjusted appropriately for the summer months. In some cases, your physician may halve the dose or switch to a different active ingredient. However, stopping your medication completely or changing the dose on your own can cause sudden spikes in blood pressure. All changes must be made with the approval of a cardiology specialist.

3. Follow the "Golden Hours" Rule

The period between 11:00 and 16:00, when the sun's rays hit the earth at their steepest angle, is when air temperature and humidity peak. Being outside during these hours, let alone doing physical activity, carries a high risk for heart patients. Even a brisk walk in the heat puts as much strain on the heart as a heavy cardio workout.

You should plan your outdoor chores, shopping, or exercise for the early, cool hours of the morning or the evening hours after the sun has set. If you absolutely must go out, you should choose shaded areas, slow down your walking pace, and take frequent rest breaks. If you feel chest pressure or shortness of breath during physical activity, you should stop immediately and move to a cool place.

4. Protect Your Body from "Thermal Shock"

Suddenly walking into an ice-cold, air-conditioned room from a sweltering environment, or taking a very cold shower while sweating, creates a thermal shock effect on the body. Blood vessels in the skin rapidly constrict when they suddenly come into contact with cold air or water. This sudden constriction causes blood pressure to spike to dangerous levels in seconds and abruptly increases the heart's workload.

Always try to keep the air conditioning temperature between 22 and 24 degrees Celsius. Ideally, the temperature difference between the outdoors and indoors should not exceed 8 to 10 degrees. Similarly, when taking a shower to cool off, make sure the water is lukewarm, not ice-cold. A lukewarm shower safely and gradually lowers body temperature, allowing you to relax without stressing your vascular system.

5. Embrace the Principle of "Lightness" in Your Diet

Heavy, greasy, spicy foods and dense carbohydrates are quite difficult to digest. To process these heavy foods, the digestive system demands a massive amount of blood to be pumped to the stomach and intestines. When the heart, already working overtime to cool the skin in hot weather, is forced to pump extra blood for the digestive system, it becomes doubly exhausted.

Switch to a diet of small, frequent meals by reducing your portion sizes. Instead of heavy pastries and fried foods, opt for foods high in water, potassium, and magnesium. Vegetables like cucumbers, tomatoes, and purslane, along with seasonal fruits like watermelon, melon, and peaches, will both replenish your fluids and spare your heart. For detailed suggestions, you can take a look at our article titled Stay Fit and Healthy in the Summer Heat: Nutritional Advice.

6. Choose "Breathable" Fabrics for Your Wardrobe

The body's most effective cooling method is sweating. However, the sweat needs to evaporate from your skin and mix with the air. Synthetic fabrics, nylon-blend garments, and tight-fitting clothes trap sweat, creating a hot greenhouse effect around the body. When body heat cannot be expelled, core temperature rises, and the heart rate climbs to dangerous levels.

Adapt your wardrobe for the summer months. Wear light-coloured, loose-fitting clothes that reflect the sun's rays. Opt for natural fibre fabrics like cotton, linen, or bamboo that allow the skin to breathe. Make it a daily habit to wear a wide-brimmed hat and sunglasses to protect your head and face from the sun when you go out.

7. Keep a Blood Pressure and Pulse Diary

When heatwaves strike, measuring and recording your body's physiological response is one of the best methods of protection. Especially if you have a diagnosis of hypertension or heart failure, knowing the course of your blood pressure throughout the day is incredibly valuable for your physician to plan your treatment correctly.

Measure your blood pressure and pulse twice a day: once when you wake up in the morning and once in the evening. Note these values in a notebook, specifying the date and time. If your blood pressure consistently drops below 90/60 mmHg or rises above 140/90 mmHg, or if your resting pulse stays above 100 beats per minute, share this data with your cardiology specialist without delay.

Differences Between Heatstroke and a Heart Attack

Although heatstroke is the first thing that comes to mind when someone collapses in hot weather, the underlying cause could be a heart attack. Distinguishing the symptoms of the two conditions is vital for administering the correct first aid.

In heatstroke, the person's body temperature rises above 40 degrees Celsius. The skin is dry, red, and extremely hot. Symptoms include a severe headache, confusion, nausea, and a rapid but weak pulse. In this situation, the person must urgently be moved to a cool place, and efforts should be made to cool their body with wet cloths.

In a heart attack, the main symptom is a severe, crushing pain felt in the centre of the chest, which may radiate to the left arm, neck, or jaw. The person's skin is pale, and they break out in a cold sweat. The pain is accompanied by shortness of breath and dizziness. If a heart attack is suspected, rather than trying to cool the patient, they must immediately be taken to a fully equipped emergency room.

When to See a Doctor and Medical Emergencies

When your heart is under strain in hot weather, it sends you some early warning signals. Paying attention to these signals and seeking medical help in time prevents permanent damage. If you experience any of the following symptoms, call the 112 Emergency Call Centre without delay or go to the nearest emergency room:

• A feeling of pressure, squeezing, or pain in the chest, back, or arm lasting longer than 5 minutes.
• Sudden and persistent shortness of breath while resting.
• Blacking out accompanied by a sudden loss of consciousness or fainting.
• The heart beating incredibly fast, irregularly, or skipping beats, as if it were about to jump out of your chest.
• Extreme fatigue, or a bluish tint on the lips or fingertips.

The Process at BHT CLINIC İstanbul Tema Hastanesi Cardiology Department

To leave nothing to chance with your heart health, undergoing a detailed cardiological check-up before the summer months begin is the safest route. At the BHT CLINIC İstanbul Tema Hastanesi Cardiology Department, our expert medical staff use advanced diagnostic methods such as ECG, Echocardiography, Exercise Stress Tests, and Holter monitoring to evaluate just how ready your heart is for the summer heat.

Summer dosage adjustments for your blood pressure, rhythm-regulating, or blood-thinning medications are meticulously planned on a personalised basis. In emergencies, our Emergency Department, which provides uninterrupted service 24/7, and our fully equipped angiography unit can intervene in any type of heart attack within minutes. To ensure a healthy summer, you can visit our appointment page or call our contact centre at 0850 811 34 00.

Frequently Asked Questions

Does blood pressure go up or down in the heat?

Because blood vessels dilate to lower body temperature in hot weather, blood pressure generally tends to drop. However, if extreme fluid loss occurs or if the person suddenly enters a cold environment, the vessels can constrict, causing blood pressure to spike suddenly.

How should blood pressure medication be used in hot weather?

Blood pressure medications should continue to be taken at the times and doses recommended by your physician. Because the winter dose might be too strong and drop blood pressure too much due to the dilation of blood vessels in the summer, you must consult a cardiology specialist to have a summer dose adjustment made.

Are heart palpitations normal in the summer?

A slight increase in heart rate is physiologically normal in hot weather because the heart pumps more blood to cool the skin. However, if the palpitations are very severe, if there are irregular beats, or if they are accompanied by shortness of breath, you must see a cardiologist.

Can heart patients go in the sea or a pool?

Yes, they can, provided they follow certain rules. Swimming should be avoided during the noon hours when the sun is directly overhead, and one should not swim on a full stomach or in a way that requires extreme exertion. Furthermore, jumping suddenly into very cold water can cause vascular spasms, so you should enter the water slowly.

This article is for informational purposes only; please consult your physician for diagnosis and treatment.