Despite a week of rain, thunderstorms and unsettled weather, the Met Office predicts that temperatures will rise significantly this weekend.
Dan Stroud, meteorologist at the Met Office, told The Press Association that he expects conditions to become much warmer, with temperatures widely above average, especially in southern areas on Saturday and Sunday.
Forecasts suggest highs could reach or exceed 30°C, although the exact peak remains uncertain.
Ahead of this potential heatwave, we spoke to Dr Olivia Buckley, GP at Nuffield Health, who explained on how sudden temperature increases can affect the body and shared some advice about how to stay safe in hot weather.
Cardiovascular strain
“The body has a really clever thermostat in the brain called the hypothalamus which detects blood temperature regularly,” says Buckley.
It continuously monitors the temperature of the blood flowing through it and acts on signals from sensors in your skin and organs to keep your internal temperature steady, she explains.
“If it detects that the temperature has gone up dramatically, one of the first things it does is try and cool the body by diverting the blood to your skin, which is called vasodilation,” explains Buckley.
“This allows the heat to be lost more easily from the skin, but does puts a bit of strain on the cardiovascular system, because your heart has to pump more regularly and more rapidly, in order to divert and flush the skin with all the blood.”
The hypothalamus is also the primary part of the brain that controls sweating.
“It will activate your sweat glands, which is a really good way of losing heat through evaporation, but by doing that you’re also putting strain on the cardiovascular system because you’re going to potentially be getting dehydrated by all that loss of fluid and salts which can also make your heart rate increase,” says Buckley.
Kidneys
Spikes in temperature can impact your kidneys through severe fluid loss and heat stress.
“Your kidneys are really good and can usually manage on quite limited fluid and will really try and limit loss by stopping you from weeing, for example, and will send a lot of clever chemicals around the body to limit its water loss,” explains Buckley.
“However, if it gets too dehydrated, then the kidneys itself don’t get enough blood supply which can issues.”
She highlights that this would only occur in the more advanced stages of dehydration.
“This wouldn’t happen to most healthy people, but it could potentially be a problem for the elderly or very little infants,” says Buckley.
Neurological symptoms
“One clever thing about your brain is that when it’s very hot, it changes your activity, so it’s normal to feel tired because your body’s very clever at saying slow down what you’re doing and go and have a lie down in the shade,” says Buckley.
Some people also experience more serious fatigue during sudden spates of hot weather.
“If you feel incredibly fatigued, that could be a sign of dehydration as well, because the blood flow to your brain might not be optimal,” says Buckley.
She adds that other neurological signs like headaches are also very common.
“Headaches can occur in the early stages of dehydration as well,” says Buckley. “You can also feel very dizzy as well with dehydration, because your blood pressure is dropping, which can lead to fainting.”
Digestion issues
“You can also feel a bit sick when you’re dehydrated, and sometimes even vomit, and that is likely to be because the blood is being diverted to your skin to try and cool you rather than to your digestive system,” says Buckley.
Heat exhaustion and heatstroke
Spikes in temperature can also lead to heat exhaustion and, in severe cases, heatstroke.
“Heat exhaustion occurs when your body overheats and loses excessive water and salt through sweating,” says Buckley. “The main symptoms are dizziness, fainting, feeling like your heart’s racing, an intense thirst and sometimes nausea and vomiting.
“You might also get muscle cramps and fatigue, and your body can start excessively sweating because it’s goes into panic mode because it’s not able to cool itself.”
Keeping an eye on these progression of these symptoms is important because it could turn into heatstroke which is much more dangerous, explains the GP.Heat exhaustion does not usually need emergency medical help if you can cool down within 30 minutes, but if it turns into heatstroke, it needs to be treated as an emergency, according to the NHS website.
“Heat stroke is essentially when your brain just gets too hot, runs out of energy, so you get extreme headache and get confused,” highlights Buckley. “Your body will divert all its attention to its vital organs, so you stop sweating and get very rapid heart rate and may start vomiting and lose consciousness.
“If you feel dizzy or faint, and feel like your heart is racing, then it’s important to seek medical attention.”
She adds that more vulnerable people, such as the elderly and infants, and people on certain medications, like diuretics, are significantly more at risk of heatstroke.
Here are her top tips on how to keep safe in sudden spikes of temperature…
“Try to keep your environment as cool as possible,” advises Buckley. “Close the curtains and blinds on windows that are facing the sunshine, and only open the windows when the outside air temperature is cooler than the inside, which is usually at night time or very early in the morning.”
Staying hydrated is also key.
“Have regular drinks, and if someone is unable to get drinks for themselves, such as small children or the elderly, make sure that they stay well hydrated,” advises the GP.
In addition, clothing can make a big difference.
“You want minimal clothing that is made of natural fibres that allow sweat to evaporate more easily,” recommends Buckley.
Fans and electrolytes can also help.
“Having a fan allows the sweat to evaporate more easily, therefore helps cool your body more effectively,” says the GP. “Having drinks with electrolytes in is also useful because you lose some salts when you sweat.”
Finally, she stresses the importance of listening to your body.
“When you’re feeling hot and tired, try to listen to your body and slow down,” recommends Buckley. “If it is incredibly hot, then you need to rest more, stay in the shade and drink plenty of water.”
