The dog days of summer can take a toll on many people and it’s smart to take precautions when dealing with the hot, humid days of the summer months. Heat can cause an extra strain, and even potentially become dangerous, for those who are already compromised by cardiovascular disease.
In general, your body should stay at a regulated temperature and has ways of doing just that, shivering (in the cold months) and sweating when it’s hot. Most people can tolerate some heat and will be just fine. But for people with a damaged or weakened heart, or older people whose bodies do not respond and recover as fast as they used to, they need to take it easy and take precautions.
When temperatures rise, the body normally sheds heat in two ways, both of which stress the heart. One way is for your body to “radiate” heat. In other words, heat in your system radiates out into cooler air. Radiation of heat causes re-routing of blood flow to the surface of the skin, which in turn makes your heart work harder by beating faster and pumping harder. On a very hot day your heart rate can quadruple compared to its rate on a normal day.
Radiation reaches its maximum when the air temperature reaches your body temperature. Literally, the heat has nowhere to go, your body resorts to sweating to cool off and eliminate heat.
Sweating is your body’s way of whisking away heat through the skin and for evaporation to provide a cooling effect. This is fine for days when the humidity is low. But on days when the humidity approaches 75 percent or higher, there is too much water vapor in the air to provide sufficient evaporation to cool you down. Evaporation also strains the heart because sweat contains minerals such as potassium, sodium and other substances needed for cardiovascular functioning and water balance. Due to this strain, your body secretes certain hormones to counteract the loss of minerals. This may result in dizziness/fainting (syncope), muscle cramps, heavy sweating, nausea or vomiting, and weak or rapid pulse.
For a person with a compromised heart this can be a serious problem for the following reasons:
- A damaged heart has decreased pumping capacity and has to work harder to produce the same cooling effect of a healthy person.
- Arteries narrowed by plaque restrict the blood flow through the body and to the skin, causing the heart to have to work harder.
- Well-known medications like beta blockers slow the heartbeat and can cause the heart to work harder to achieve the same cooling effect.
- Diuretics can increase the risk of dehydration, so any sweating can take an extra toll on your system.
- Other medical issues such as diabetes, previous stroke, being overweight or having high blood pressure can all have a compounding effect on anyone, let alone someone with an existing heart condition.
Beat the Heat
Despite the potentially dangerous effects that heat can have on someone with a heart condition, there are some simple, common-sense precautions you can take to make sure that you stay safe, cool and healthy.
- Limit exercise times to early morning or later in the evening when the temperatures are cooled down a bit. Or, exercise in a gym or walk at the mall where there is air conditioning.
- Cool showers or baths, or putting a cool towel or ice pack on the back of your neck or under your arms, are good ways to bring down body heat quickly.
- If you don’t have air conditioning, put a fan on the shady side of your house to draw in cooler air from the outside.
- Maintain fluid intake for hydration. Decaffeinated beverages are best, as caffeine is a diuretic and can have the opposite effect from hydration.
- Eat light food with high water content. Fruits, salads and cool soups can help you maintain vitamin and mineral balance but not strain your digestive system.
The summer heat can be a cause for concern and something people with cardiovascular compromises have to be aware of, but it does not mean the end of summer enjoyment. People with a compromised heart condition just need to be more vigilant and take a few common-sense precautions. As always, if you feel dizzy, or have any of the symptoms mentioned earlier, please contact your health care provider right away.