When the temperature rises, your heart has to beat faster and work harder to pump blood to the surface of your skin to assist with sweating to cool your body. This happens through dilation of the small blood vessels (or arteries) close to the surface of the skin). This can cause a drop in blood pressure as well as an increase in heart rate to try and expel heat from the body. If you have a heart condition, this may make you feel dizzy or faint, so it’s important that you keep your cool in the heat.
If your body can’t cool itself enough, extra strain is put on the heart and organs can begin to suffer damage – a potentially fatal condition known as heat stroke.
Anyone can suffer heat stroke, but people with heart disease and other cardiovascular diseases are at greater risk. If you have heart disease or have heart failure, your heart may not be able to work as hard in the heat to maintain cooler body temperatures.
Some medications prescribed to patients with heart conditions reduce water to reduce the amount of pressure on the heart, however these medications may reduce a person’s ability to cool off in the heat. If you have been prescribed diuretics or beta-blockers, ask your doctor about safe levels of water to drink for hot conditions versus milder temperatures. Drinking too much water will cause just as much problem as drinking too little. A rough guide is to go by the colour of your urine – it should be a pale, straw colour, almost clear. If it’s darker than this, try adding an extra glass or two in the day.
Symptoms of Heat Exhaustion
Heat exhaustion is a warning sign that can lead to heat stroke. The symptoms may include:
- Heavy sweating with cool, clammy skin
- Feeling faint
If you experience any of these, find a cool spot, rest, take off any layers of clothing that you can, and drink some cool water. Apply a damp flannel to your forehead or run your wrists under cool water to bring your body temperature down.
Symptoms of Heat Stroke
Heat stroke is an emergency. If you experience the following symptoms, apply cool water to your skin immediately and seek medical help.
- High fever
- Hot, dry skin without sweating
- Pounding pulse
- Nausea and vomiting
- Fainting or unconsciousness
Find a cool spot immediately, apply cool water to your skin and drink cool water which can help you stop heat exhaustion before it worsens.
Tips for Staying Safe in the Heat
Everyone is at risk of heat stroke, but the risks are even higher for those with heart disease or high blood pressure. Remember, while heat stroke may happen after only a short time in high temperatures, heat exhaustion results from days of exposure to high heat and can progress to heat stroke. A long period of hot weather over a few days can make you ill more slowly and make it harder for you to recognise your symptoms.
Here are some tips to stay cool and safe.
- Avoid vigorous physical activity in high heat. No task or exercise program is worth risking your life for. Make plans to complete a task when the weather cools. Move your exercise program to an indoor gym with air-conditioning or have swim instead.
- Stay hydrated by drinking water and drinks that contain electrolytes. Carry water with you, especially when travelling. Water is critical to all functions in your body. Electrolytes not only help balance hydration in your body, they also help keep the body’s natural electrical system that governs your heartbeat working correctly.
- Avoid caffeine and alcohol. These beverages can contribute to dehydration.
- Choose a cooler environment. Switch your air conditioning on. If you don’t have air conditioning, use fans and periodically apply cool water to your skin. If your home is still not cool enough, go to an air-conditioned shop, library – anywhere that’s cool enough to keep your body temperature within the normal range. Also, if you are not able to leave your home, do not be shy about asking for help from others.
- Wear a hat outside and stay in the shade. Don’t sit or walk in the sun for long periods. You may not feel the effects until it’s too late.
- Put a wet flannel/face-washer on your forehead. Wring out a flannel after running it in cold water. Apply to your forehead and relax in a cool spot.
- Run your wrists under cold water. This can help to bring your body temperature down.
- Spray a water bottle on yourself regularly. You can get a simple ‘mist’ bottle similar to a cleaning bottle (make sure it doesn’t contain anything but water and has never contained chemicals). Fill with cool water and spray regularly over yourself.
- Wear light coloured, lightweight clothing. Light coloured clothing reflects the sun’s rays, rather than absorbing them like dark clothing. Heavy-weight fabrics like polyester will trap body heat in, so choose lightweight fabrics like cotton or linen that allow heat to escape and better allow for your natural sweating processes to cool you off.
- Wear sunscreen. Apply it before you go outside. If you get burnt it will be even harder for your body to stay cool.
Is It Ever Too Hot for Your Heart to Exercise?
When the temperature reaches 70 degrees Fahrenheit (21 degrees Celsius) and the humidity is 70 percent or higher, your heart has to begin to work harder just to cool your body. When the outdoor temperature climbs into the 80s (Fahrenheit) or high 20s (Celsius) or beyond and there is high humidity, the risk to your health also rises. If you have heart disease, you should avoid exercising when the temperature and the humidity are both high. It would be better to avoid intense exercise until the temperature has dropped or switch your exercise to an air conditioned venue or a swimming pool.
Have you got any other tips to share? What do you do to keep cool?