We’ve been inundated with pleas urging us to keep hydrated amid the UK’s record-breaking heatwave.
But how do you know whether you’ve actually had enough water?
It might sound obvious, but simply looking at the colour of your urine can provide the answer.
So if you plan to brave Britain’s Saharan-esque 40C temperatures today, experts recommended you follow a handy guide used widely within the NHS.
Similar to a paint chart at B&Q, it charts a scale from clear to dark brown.
Clearer colours suggest you have had enough water for now, but the opposite end of the spectrum could be a warning sign of severe dehydration or potentially worse.
Clear to pale urine (number one) suggests a person is well hydrated, while a light yellow urine (number two) is ‘ideal’, the health service guide states. A darker yellow or pale honey-coloured urine (number three) means a person may need to hydrate soon and a yellow, cloudier urine (number four) is a sign to drink. Darker yellow urine (number five) means a person is starting to become dehydrated, while an amber-coloured urine (number six) is ‘not healthy’ and means the body ‘really needs more liquid’, the NHS says. Orange urine (number seven) means a person is becoming ‘severely dehydrated’, while a very dark red or brown urine (number eight) means a person needs to see their GP — and the colour may not be down to not drinking enough
WHAT DOES THE URINE GUIDE SHOW?
Colours 1-3 suggest normal urine
1. Clear to pale yellow urine suggests that you are well hydrated
2. Light/transparent yellow urine suggests an ideal level of hydration
3. A darker yellow/pale honey coloured urine suggests that you may need to hydrate soon
Colours 4-8 suggest you need to rehydrate
4. A yellow, cloudier urine colour suggests you are ready for a drink
5. A darker yellow urine suggests you are starting to become dehydrated
6. Amber coloured urine is not healthy, your body really needs more liquid. All fluids count (except alcohol)
7. Orange/yellow urine suggests you are becoming severely dehydrated
8. If your urine is this dark, darker than this or red/ brown, it may not be due to dehydration. Seek advice from your GP
Johanna Hignett, a registered nutritionist, told MailOnline the urine colour chart is ‘simple and useful in this hot weather’.
She added: ‘The darker the urine colour the greater the chance of your fluid levels being low in your body.
‘It’s such an easy and simple tool to use to prompt people to remember to drink.’
However, others note the urine scale is not a full-proof way of knowing whether you are dehydrated.
This is because the colour can also be affected by what you drink, the speed at which you drink and certain medications.
For example, urinary tract infection medicine pyridium can turn urine red, anti-inflammatory drug sulfasalazine can cause it to turn orange, and antidepressant amitriptyline can turn it blue or green.
Britons should also be aware of other tell-tale dehydration symptoms, such as feeling thirsty, lightheaded and tired.
Soaring temperatures increases the risk of becoming dehydrated.
Under normal conditions, people lose fluids through sweat, tears and urine, which is replaced by drinking, as well as eating foods with a high water content, such as cucumber, tomatoes and melon.
But when a person is overexposed to the sun, the body loses more water than usual, along with essential body salts such as sodium and potassium, through sweat.
The NHS guide, which trusts tend to put together themselves, labels urine on a scale of one to eight.
Clear to pale urine (one) suggests a person is well hydrated, while a light yellow urine (two) is ‘ideal’, the health service guide states.
A darker yellow or pale honey-coloured urine (three) means a person needs to drink soon and a yellow, cloudier urine (four) should swig some water as soon as possible.
Darker yellow urine (five) means a person is starting to become dehydrated, while an amber-coloured urine (six) is ‘not healthy’ and means the body ‘really needs more liquid’, the NHS says.
Orange urine (seven) signals someone is becoming ‘severely dehydrated’, while very dark red or brown urine (eight) should warrant a trip to the GP. This is because the dark colour may not be down to not drinking enough, instead it could be a sign of a urinary tract infection, hepatitis or liver disease.
Adults are advised to drink six to eight glasses of fluid every day — around 1.5 litres — with all drinks apart from alcohol counting towards the total.
But the amount each person needs depends on their size, physical activity levels and underlying conditions, as well as the weather.
Amid the heatwave, Dr Simon Cork, a senior lecturer in physiology at Anglia Ruskin University, said people can use urine colour as a good indication of whether they are drinking enough.
Health chiefs have warned Britons to stay hydrated as temperatures today hit 40.2C (104.4F) at Heathrow — breaching the former high of 38.7C (101.7), set in 2019
Hottest day in history: Britain hits a record 40.2C – first time ever in the forties
Britain today experienced its hottest day on record as temperatures soared past 40C (104F) amid growing rail travel chaos as schools shut again and millions of people respond to the extreme heat by working from home.
The mercury hit an unprecedented 40.2C (104.4F) at London Heathrow Airport at 12.50pm – around an hour after a reading of 39.1C (102.4F) in Charlwood, Surrey, beat the previous all-time UK high of 38.7C (101.7F) in Cambridge in July 2019. In third place is 38.5C (101.3F) in Kent in August 2003, and 38.1C (100.6F) in Suffolk yesterday is fourth.
Elsewhere today, the mercury got up to 38.8C (101.8F) at Kew Gardens in West London around noon – also beating the all-time high. It was 38.1C (100.6F) at St James’s Park in Central London and 37.7C (99.9F) in Chertsey, Surrey.
Forecasters said an absolute maximum of 43C (109F) is possible later on – and the highs in England are equal to the warmest spots anywhere in Europe today. The UK is also hotter than Jamaica, the Maldives and Barbados.
The Met Office also confirmed that last night was the warmest night on record in Britain, with temperatures not falling below 25C (77F) in many areas of England and Wales. The highest overnight minimum in the UK last night was 25.9C (78.6F) at Emley Moor in West Yorkshire, while it was 25.8C (78.4F) at Kenley in Croydon, South London.
This smashed the previous record of 23.9C (75F) in Brighton set on August 3, 1990. It comes one day after Wales had its hottest day ever with 37.1C (99F) in Hawarden, Flintshire – beating a record set in the same village in 1990.
The method works because the kidneys cleanse the blood of toxins and transforms waste into urine.
If a person has not drank enough water, the kidneys produce a very concentrated, dark-coloured urine, Dr Cork explained.
He added: ‘If you are sufficiently hydrated (or even excessively hydrated) then your kidneys will get rid of that excess water in the form of very dilute, clear urine.
‘The clearer your urine is, the more hydrated you are.’
But record-high temperatures will be causing people to more fluids through sweat, lowering the amount of water in the circulatory system.
Dr Cork said: ‘This can have detrimental effects on blood pressure.
‘If blood pressure falls too low then our organs are not adequately perfused by blood and, in extreme cases can start to fail.’
However, Professor Hugh Montgomery, chair of intensive care medicine at University College London, told MailOnline urine colour alone ‘isn’t a good guide’ for hydration levels.
The colour of urine is also affected by the type of drink you consume, how quickly a person drinks and certain medications.
Studies have warned that it should not be used on its own to assess whether people are hydrated.
But experts said other signs can also point to whether a person should be drinking more.
Experts warned that strong-smelling urine and passing urine fewer than four times a day are also signals that a person isn’t drinking enough.
Feeling thirsty, dizzy, lightheaded and tired are all signals of dehydration, as are a dry mouth, headaches, weak muscles and constipation.
Professor Mike Tipton, a physiologist at the University of Portsmouth, told MailOnline that it is essential people drink enough, especially when it’s hot outside.
He said: ‘Dehydration compounds the strain on the heart and circulation experienced during heat waves and can compromise your ability to control body temperature.
‘Those particularly susceptible to dehydration include the young and the elderly.’
Experts urged those who have dark-coloured urine or other dehydration symptoms to turn to water and stay clear of coffee and alcohol.
Water is the best choice of soft drink for hydrating as it is calorie and sugar free and ‘gives a brilliant refreshing drink in hot weather’ when chilled, Ms Hignett said.
Meanwhile, Dr Cook advised people to avoid caffeine and alcohol-based drinks as they are diuretics and make it harder for the kidneys to retain water, leading to more frequent urination.
And he urged Britons to keep drinking throughout the say, rather than drinking ‘large amounts in short bursts’.
Dr Cork added: ‘The water we ingest needs to be compartmentalised into the right parts of the body.
‘Drinking a whole pint of water very quickly may trick the kidneys into thinking your sufficiently hydrated and you may end up peeing that water out quite quickly.’
Professor Montgomery said that Britons can dodge dehydration by staying cool so they don’t sweat and loose fluids in the first place.
Those venturing outdoors should limit the time as much as possible, wear light and loose clothing and wear a broad-rimmed hat.
Are YOU drinking enough water? Experts reveal how much to consume to stay hydrated as temperatures in parts of the UK are expected to hit 43°C today
Around two thirds of Britons do not drink enough water, researchers have warned — as much of the UK roasts in record-breaking heat.
The human body is made up of nearly 60 per cent water, including 75 per cent of the brain and 71 per cent of the liver, so staying hydrated is vital, particularly in hot weather.
Experts say people should drink at least two litres of water every day, although this is a rough estimation and actually depends on a person’s age, gender and weight.
Now a new study for Austrian company Waterdrop, which found that 66 per cent of the population is not drinking enough water every day, has led to the creation of a ‘My Hydration’ app.
It estimates how much water a person needs to consume every day and allows them to track their progress by entering what they have drunk and when.
As an example, it suggests that 2,600ml should be consumed by men and women in their 20s or 30s who are an average weight.
This decreases with age but increases with weight, while more water should be drunk if a person is exercising or if it is hot.
A person in their 50s should be looking to drink around 2,220ml of water, according to the app.
Dehydrated Britain: Around two thirds of people in the UK do not drink enough water, researchers have warned. The graphic above shows how much water you should drink a day on average (about 2.6 litres), but broken down into more than just water. Your intake can also come from coffee, tea, ice cream, cola, vegetables and fruit (pictured)
The human body is made up of nearly 60 per cent water, including 75 per cent of the brain and 71 per cent of the liver, so staying hydrated is vital, particularly in hot weather (stock image)
A study for Austrian company Waterdrop, which found that 66 per cent of the population is not drinking enough water every day, has has led to the creation of a ‘My Hydration’ app (pictured)
WHY IS IT IMPORTANT TO DRINK AT LEAST 2 LITRES OF WATER?
- It increases brain power and concentration
- Flushes out unwanted toxins
- Improves digestion and gut health
- Maintains kidney health
- Improves or maintains healthy skin
- Decreases headaches and boosts mood
- Hydrates the body and skin
The NHS recommends drinking 6 to 8 glasses of water a day regardless of gender, age or weight, while in the US, the National Academies of Sciences, Engineering, and Medicine has broken it down more specifically.
It suggests that men require around 3,600ml of fluid, while women need 2,600ml.
This covers fluids from water, other beverages and food — with about 20 per cent of daily fluid intake usually coming from food and the rest from drinks.
For example, a medium-sized cucumber is made up of around 96 per cent water, similar to lettuce, radishes and celery.
An apple is 84 per cent water and strawberries 91 per cent.
People can also get a portion of their water intake from tea and coffee, with a medium cup of the former equating to 342ml and the latter 225ml.
But as Britain continues to swelter in stifling temperatures, the amount of sweat expelled during these months increases, which makes it particularly important to replace the fluid lost in sufficient quantities.
According to the research by Waterdrop — a global hydration specialist — around two-thirds of Britons do not drink enough water.
The survey showed that this rises to 79 per cent in people over 65 years old.
Around 90 per cent of participants also said they had experienced signs of dehydration, including water retention, dry mouth, headaches and more.
But dehydration can also have more far-reaching effects, including reduced immunity and joint pain.
Research has even linked it to acid reflux, heart disease, type 2 diabetes and Alzheimer’s disease.
Waterdrop’s study, which sampled 1,000 people from the UK between the ages of 17 and 99, found that 26 per cent did not feel the need to drink water and 45 per cent never paid much attention to what they should be drinking.
Drinking water helps hydrate the kidneys, improves digestion and gut health, rejuvenates the skin and prevents fatigue.
Navin Khosla, a pharmacist at the online health clinic FROM MARS, said: ‘Staying hydrated is the key to feeling fit and healthy during these hot periods, and you shouldn’t be taking drinking water for granted in a heatwave — it really is essential.
‘I would try to recommend drinking 20 per cent more than your usual intake, replacing the consumption of tea, coffee, alcoholic beverages, and sugary drinks with water.
As an example, it suggests that 2,600ml should be consumed by men and women in their 20s or 30s who are an average weight
‘This change may not be to everyone’s taste, so you could add flavour to your drinks through fruits, whilst milk and smoothies are also good options to help replenish a lack of fluids.’
He added: ‘Some of the advice I can give you is perhaps more forthright, and I cannot stress enough the importance of checking your wee.
‘This may not be a common thought for most people, but the colour and smell of your urine is a key indicator when it comes to dehydration, and it should become apparent to you if it is dark yellow in colour and strong smelling.’
About 20 per cent of daily fluid intake usually comes from food and the rest from drinks. For example, a medium-sized cucumber is made up of around 96 per cent water
Previous research, which also involved a survey of the British public, found that less than a quarter of adults regularly drink the recommended two litres of water a day, while one in seven admit drinking more alcohol than water.
Around half said they had a tea or coffee instead of water, with 30 per cent saying ‘they need caffeine more’.
More than a third of Britons thought water was boring.
Another study found that as little as a 2 per cent reduction in optimum hydration leads to measurable cognitive loss (which returned when the study participants were fully hydrated), affecting performance in tasks that require attention, memory skills, feelings and judgements.
A 2 per cent reduction is about one litre of water.
That same tiny degree of dehydration has been shown to affect blood vessels in a similar way that smoking a cigarette does — even in healthy young men, as a study published in the European Journal of Nutrition in 2017 found.
GP Dr Ellie Cannon said: ‘Water is the healthiest way to hydrate; it energises us, aids digestion and weight loss and improves the complexion to name just a few of the benefits.
The amount of water you should drink increases with your weight (as shown in this graphic)
WHAT HAPPENS WHEN YOU DON’T DRINK ENOUGH WATER?
- The body is prone to more headaches and fatigue
- It becomes difficult to stay focused and concentrate during the day
- The kidneys, gut and digestive system don’t function efficiently
- The skin will become dehydrated and possibly irritated
- Your mood will be negatively impacted
- Energy levels decrease
- Unwanted toxins remain in the body
‘Despite this, many people are drinking far less than they should and their health could be suffering as a result.’
She added: ‘Simple tricks like adding a little sparkle to your water can help encourage you to drink more water every day and you’ll be feeling healthier and re-energised before you know it.’
Water is essential for our bodies. We need it to take valuable chemicals, minerals, nutrients and oxygen into our cells.
It also helps maintain our body temperature (through sweat) and helps get rid of waste products.
It acts as a shock absorber and lubricant for our joints and tissues, eyes, nose and mouth, helping to protect our organs.
Not only do we need water for these vital functions, we are ourselves largely made up of water — around 60 per cent.
As we get older, this changes — so while babies might be 75 per cent water, in older people this could be as low as 55 per cent.
One reason is the age-related decline in muscle mass (muscles are about 75 per cent water).
So being hydrated really does matter, and it is clear from research that even the smallest amount of dehydration can have a big impact on the body and the brain.
To help combat dehydration among the UK population, Waterdrop has developed its hydration application tracker. This allows people to track their drink consumption and set daily goals.
The hydration tracker is available to download for both iOS and Android.
HOW MUCH WATER SHOULD YOU BE DRINKING?
One formula for how much water you should be drinking is as follows:
Step 1: Take your weight (in lbs) and divide it by 2.2.
Step 2: Multiply that number by your age.
Step 3: Divide that sum by 28.3.
Step 4: Your total is how many ounces of water you should drink each day.
Divide that number by eight to see your result in cups.