What are the symptoms of dehydration? Signs to spot as ‘serious’ health warning issued in UK heatwave

Temperatures are forecast to hit 30C in parts of the UK this week

Brits are being warned to be wary of the “serious” health implications of the hot weather this week, as the UK braces for a sweltering heatwave.

Forecasters say temperatures could reach 34C in the south east of England on Friday (17 June), with 27C to 30C weather expected across most of England and Wales, meaning the country will be hotter than parts of Jamaica and the Maldives.

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Brits are being warned to be wary of the “serious” health implications of the hot weather (Composite: Kim Mogg / NationalWorld)

Dr Radhika Khosla of the University of Oxford, said: “The health implications of rising temperatures in the UK are serious.

“Important physiological changes occur in response to high temperatures including changes in our circulatory, nervous and respiratory systems.

“When these adaptive measures are not enough, the risk of cardiopulmonary and cardiovascular problems increases among older adults, young children, people with chronic conditions, athletes and outdoor workers.

“Severe heat disrupts sleep, impairs cognitive performance and is associated with increased risk of suicide or hospital admission for mental illness.”

The UK Health Security Agency (UKHSA) has issued a level 2 heat-health alert for a large part of southern and central England, while a level 1 alert is in place for northern England.

Experts are urging people to take care in the hot weather and to be aware of the direct health effects of extreme heat, including heatstroke and dehydration.

What are the symptoms of dehydration?

Dehydration is a common symptom of extreme heat and occurs when the body loses more fluid than it is taking in.

When the normal water content of your body is reduced, this upsets the balance of salts and sugar in your body, affecting the way it functions. If left untreated, symptoms can worsen and become a more serious problem.

Early warning signs of dehydration include:

  • Feeling thirsty
  • Dark yellow and strong smelling urine
  • Feeling dizzy or lightheaded
  • Feeling tired
  • Dry mouth, lips and eyes
  • Urinating little and fewer than four times per day

A lack of fluids is the most common cause of dehydration, but it can occur more easily if you are suffering from heatstroke, have a high temperature of 38C or above, have diabetes, or you have been vomiting or have diarrhoea.

How can I treat dehydration?

If you are severely dehydrated your body needs to be replenished with the sugar, salts and minerals it lost.

Oral rehydration sachets are a good way to do this, which a pharmacist can recommend, or you can drink lots of water. Try to avoid large amounts of tea or coffee as these are high in caffeine.

If you feel too hot, it is advised that you move to a cool place, lie down with your feet slightly raised, and apply cold water to your skin to help bring your body temperature down.

You should call 999 or go to A&E if:

  • you are feeling unusually tired
  • you are confused and disorientated
  • any dizziness when you stand up doesn’t go away
  • you haven’t urinated for eight hours
  • your pulse is weak or rapid
  • you have fits (seizures)

These symptoms can be signs of serious dehydration and require urgent treatment.