This Is How A Heatwave Impacts Your Body

11 hours ago 1

A rare ‘red’ extreme heat alert has been issued ahead of soaring temperatures in south-east England this week.

Temperatures are expected to reach 37°C, with the Met Office saying “there remains a chance of this being exceeded in places”.

Under the previous amber alert (which has since been upgraded to red) elderly people and those with underlying health conditions were flagged as most at-risk from the warmer temperatures.

However the red alert now indicates “a risk to life for even the healthy population”.

We looked into exactly how such high temperatures can impact the body – and why it’s so important to try and stay cool.

The heart

When it’s hot for an extended period of time, the body’s internal temperature may rise, making your heart rate increase and vessels expand to bring more blood to the outer layers of skin, where the heat is then released.

If this heat isn’t released fast enough or the surrounding air is warmer than the body, your sweat glands will try to cool you down.

This is all well and good, but Dr Luke Powles, associate clinical director of Health Clinics Bupa Global and UK, told HuffPost UK sweating means a loss of fluid.

“This can lead to a drop in blood pressure,” he explained, “causing the heart to beat more rapidly, making the heart work harder to maintain a cooler body.”

“People with heart conditions and other underlying medical problems, and those on certain medications, can be particularly sensitive to increasing temperatures and therefore at a higher risk of becoming unwell in a heatwave,” he said.

This is why it’s imperative to stay hydrated, and keep cool where possible.

The brain

Part of the brain called the hypothalamus controls our core body temperature and is also responsible for sending signals to the skin to start sweating.

However when it becomes too hot, these signals may not get through properly.

While we shouldn’t see this from the forecast temperatures, Dr Powles explained that “in extreme cases where your body temperature goes over 40°C, this can stop nerve fibres from working properly, which means the messages may not get through to and from the brain”.

When the body temperature goes higher than normal it can lead to dizziness, feeling weak and tired, poor co-ordination, and even problems with balance or thinking, said Dr Powles. “Your skin can also turn pale, cold and dry with loss of sweating, if it stops receiving messages from the brain.”

Dr Kenny Livingstone, a registered GP and founder of ZoomDoc, said at a cellular level; membranes, mitochondria and DNA can become damaged in extreme heat which raises the risk of stroke and swelling in the brain.

“If high internal core body temperatures are sustained – it can ultimately prove fatal,” he added.

The lungs

Another symptom of heat-related illness is breathing more quickly. Dr Powles said the hot weather can put more strain on the lungs, especially if you already suffer from conditions such as COPD or asthma.

The summer months also mean there are higher levels of pollen and, in some cities, air pollution, which can also impact your breathing.

“If you feel the heat is negatively impacting your breathing, try staying indoors more often, in well-ventilated areas,” Dr Powles advised.

Liver

The hot weather can also be “dangerous” for the liver, which is another thermosensitive organ. “Serious conditions such as heatstroke can damage liver cells, reflected by increased levels of liver enzymes in the blood,” Dr Powles explained.

Heatstroke is when the core body temperature rises above 40°C and the body’s internal systems begin shutting down. This can impact the nervous system and, if left untreated, can harm specific organs too.

“At its worst, this can lead to overall liver damage, although liver injury is often self-limiting,” said Dr Powles. “If you are suffering from any symptoms of heatstroke, it’s vital to get treatment immediately.”

Kidneys

Studies have linked heatwaves to an increased likelihood of kidney disease for those increasingly exposed to heat.

“As well as dehydration and a drop in blood pressure, both of which can harm the kidneys, in hot weather the body’s energy requirements can exceed its ability to produce energy, causing muscle cells to break down and release a protein called myoglobin and other products into the bloodstream,” Dr Powles explained.

“Some of these breakdown products (including myoglobin) can be toxic to the kidneys and can directly damage them.”

He added that while illnesses such as heatstroke can eventually be a cause of kidney failure, it’s important to know that this would result from a combination of events and, if treated, can be managed properly before it reaches this stage.

“Rehydrating the body will be essential in treating and protecting the kidneys from heatstroke,” he said.

UKHSA health advice for the hotter weather

Keep your home cool by closing windows and curtains in rooms that face the sun.Look out for those who may struggle to keep themselves cool and hydrated – older people, those with underlying conditions and those who live alone are particularly at risk.Drink plenty of fluids and avoid excess alcohol.Never leave anyone in a closed, parked vehicle, especially infants, young children or animals.Check that fridges, freezers and fans are working properly.Try to avoid direct sunlight, especially between 11am and 3pm – if you do go outside, cover up with suitable clothing, such as an appropriate hat and sunglasses, and seek shade and apply sunscreen regularly.Avoid physical exertion in the hottest parts of the day.Make sure you take water with you if you are travelling.Take care and make sure to follow local safety advice if you are going into the water to cool downCheck medicines can be stored according to the instructions on the packaging.If you are going to do a physical activity (for example, exercising or walking the dog), plan to do these during times of the day when it is cooler, such as the morning or evening.