After a week marked by persistent rain, thunderstorms, and generally unsettled conditions, the Met Office has issued a forecast predicting a significant surge in temperatures across the UK this weekend.
Dan Stroud, a meteorologist at the Met Office, informed the Press Association that he anticipates much warmer weather, with temperatures expected to be widely above average, particularly in southern regions on both Saturday and Sunday. Forecasts indicate that highs could reach or even exceed 30°C, though the precise peak temperature remains uncertain.
Ahead of this potential heatwave, Dr Olivia Buckley, a GP at Nuffield Health, offered crucial insights into how sudden temperature increases can impact the human body and provided essential advice on staying safe in hot weather.
Cardiovascular Strain
“The body has a really clever thermostat in the brain called the hypothalamus which detects blood temperature regularly,” explains Dr Buckley. This internal system continuously monitors the blood’s temperature and responds to signals from sensors in the skin and organs to maintain a stable internal temperature.
“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,” Dr Buckley clarifies. “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 also plays a primary role in controlling 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,” she adds.
Kidney Health
Sudden temperature spikes can affect kidney function due to 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,” Dr Buckley explains. “
However, if it gets too dehydrated, then the kidneys itself don’t get enough blood supply which can issues.” She notes that this would typically only occur in 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,” she cautions.
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 Dr Buckley.
Some individuals may experience more severe fatigue during hot spells. “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,” she warns. Other common neurological signs include headaches. “Headaches can occur in the early stages of dehydration as well,”
Dr Buckley states. “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,” Dr Buckley explains.
Heat Exhaustion and Heatstroke
Elevated temperatures 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 Dr 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.”
Monitoring the progression of these symptoms is crucial, as heat exhaustion can escalate into the far more dangerous condition of heatstroke, the GP explains. While heat exhaustion typically doesn’t require emergency medical attention if the individual can cool down within 30 minutes, heatstroke is a medical emergency, according to NHS guidance.
“Heat stroke is essentially when your brain just gets too hot, runs out of energy, so you get extreme headache and get confused,” highlights Dr 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 vulnerable groups, including the elderly, infants, and those on certain medications like diuretics, face a significantly higher risk of heatstroke.
Top Tips for Staying Safe:
Dr Buckley offers her key recommendations for navigating sudden temperature spikes:
- Keep your environment cool: “Try to keep your environment as cool as possible,” she advises. “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.”
- Stay hydrated: “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,” the GP recommends.
- Choose appropriate clothing: “You want minimal clothing that is made of natural fibres that allow sweat to evaporate more easily,” Dr Buckley suggests.
- Utilise fans and electrolytes: “Having a fan allows the sweat to evaporate more easily, therefore helps cool your body more effectively,” she explains. “Having drinks with electrolytes in is also useful because you lose some salts when you sweat.”
- Listen to your body: “When you’re feeling hot and tired, try to listen to your body and slow down,” Dr Buckley stresses. “If it is incredibly hot, then you need to rest more, stay in the shade and drink plenty of water.”