Hot weather means your body has to work harder to keep its core temperature to normal levels, and this puts extra strain on your heart, lungs and kidneys. This means that you can be at greater risk if you have a heart condition. So it's particularly important to stay cool and hydrated.

Drinking plenty of fluids will help to make up for the fact that you are sweating more than usual and stop your blood pressure from dropping too much.

What can I do to keep cool?

There are some simple things you can do to keep cool in hot weather:

• keep hydrated by drinking plenty of water or other drinks. Water is best but milk, sports drinks, diluted squash, fruit juice, tea and coffee all count (although it's best to stick to no more than three to five cups of tea or coffee a day, or switch to decaffeinated versions). If you've been told to restrict your fluid intake, because you have heart failure for example, you should speak to your GP.
• avoid drinking too many alcoholic drinks. They can make you more dehydrated
• enjoy cold foods, such as salads and fruit, which have a high water content and are good sources of vitamins and minerals
• try to keep your home cool when you're staying indoors. Cover windows exposed to direct sunlight with shutters if you have them, or blinds or curtains if you don't. Open windows if it's cooler outside than in your home. Turn off any lights or electrical equipment you don't need, as they can make your home hotter
• spend time in the coolest part of your house, especially for sleeping
• wear light, loose fitting clothes
• stay out of the sun in the hottest part of the day between 11am and 3pm
• it can be cooler to go out, especially if you can spend time in the shade. Apply sunscreen, wear a hat and carry some water with you
• avoid extreme physical exercise.

What if I'm feeling ill in the heat?

These are four quick ways to feel better if you are feeling ill in the heat: 

• move to a cool place
• lie down and raise your feet slightly
• drink plenty of water
• cool your skin - spray or sponge with cool water and fan yourself. Ask someone else to do this for you if that's an option for you. Cold packs or ice packs around the armpits or neck are good too.If your symptoms persist, seek medical advice. 

Hot weather and heart conditions

Angina

If you use a GTN spray to control your angina you should take extra care in hot weather. GTN spray can dilate your blood vessels quickly, which causes your blood pressure to suddenly drop and you may feel faint.   

Heart failure

It’s particularly important to stay cool if you have heart failure - where your heart doesn't pump blood around your body as well as it should. If you’ve been told to restrict your fluid intake, speak to your GP about other ways to keep cool during summer. If you take water tablets and are dizzy or light headed let your doctor know. Your medication can then be reviewed or adapted as necessary.

Heat stroke

Losing too much body fluid can increase your internal body temperature, which could be life-threatening if left untreated.  Symptoms of heat stroke include sweating, cold clammy skin, dizziness, fainting, muscle cramps, heat rash, oedema (swelling) in the ankles, shallow or fast breathing, nausea and vomiting. 

If you suspect that you or someone else has heat stroke, get medical attention immediately.

Who is most at risk?

• elderly people and very young children have more difficulty in regulating their temperature and so can be more at risk from extreme temperatures
• older people, particularly if they are over 75, or living on their own without much social contact, or in a care home
• people with long-term health conditions, including heart or circulatory conditions, lung conditions, kidney problems, diabetes and Parkinson's disease
• people who find it harder to avoid the heat or to adapt their behaviour, such as people who are bed-bound, or have a disability, or have dementia, or who work outdoors.

Research shows that most people don't see themselves as at risk from hot weather, even when they are. In hot weather, check on your friends and relatives regularly to make sure they are cool and comfortable.

Content sourced from the British Heart Foundation (bhf.org.uk).