In a hot climate such as the UAE, long summers, outdoor work, sport and travel all increase how much fluid the body loses. Many people only realise they have been under-drinking when a stone causes sudden pain. This article explains why heat matters, who is most at risk, how much to drink according to published guidance, and which symptoms need urgent care.
Why heat raises the risk of kidney stones
In hot weather the body loses water through sweat. If that water is not replaced, the kidneys make less urine, and the urine becomes more concentrated. Minerals such as calcium and oxalate are then more likely to form crystals that can grow into a stone. The EAU 2026 urolithiasis guidelines list high ambient temperatures among the environmental risk factors for stones.
Research supports this. A study led by the Children’s Hospital of Philadelphia, reported by ScienceDaily, looked at more than 60,000 people with kidney stones in five US cities. Stone presentations rose as mean daily temperatures climbed above 10°C in all cities but one, and the effect peaked within 3 days of hot weather. The researchers also suggested that the number of hot days may predict risk better than the average temperature over a year. The main guide to kidney and ureteric stones explains how stones form.
Who is most at risk in a hot climate
Anyone can become dehydrated in summer heat, but some people lose more fluid or find it harder to drink regularly:
- Outdoor workers, such as those in construction, delivery or security, who sweat for hours and may have limited breaks
- People who exercise or play sport outdoors or in warm gyms
- Travellers arriving from a cooler climate, or spending long days sightseeing, flying or driving with few toilet stops
- People who have had a stone before; the ScienceDaily report notes that higher temperatures probably matter most for people already prone to stones
- Children, whose fluid needs rise in hot weather and with exercise, according to the NIDDK; see kidney stones in children
Signs you are not drinking enough
The NHS lists these signs of dehydration in adults and children:
- feeling thirsty
- dark yellow, strong-smelling urine
- passing urine less often than usual
- headache, dizziness or feeling light-headed
- feeling tired
- dry mouth, lips and tongue, and sunken eyes
Urine colour is the simplest daily check. The NHS advises drinking enough during the day for your urine to be pale; dark urine means you need to drink more.
How much to drink in hot weather
Needs vary with body size, activity and sweating, but published guidance gives a starting point:
| Guidance | What it says |
|---|---|
| NHS, preventing kidney stones | Adults: 2.5 to 3 litres of water a day. Children: 1 to 2 litres a day. |
| EAU 2026 guidelines | Fluid intake of 2.5 to 3.0 litres a day, aiming to pass 2.0 to 2.5 litres of urine. Water is the preferred fluid. |
| CDC NIOSH, workers in heat | For moderate activity in moderate conditions, 1 cup of water every 15 to 20 minutes, starting before you feel thirsty. |
On hot days, or when working or exercising outdoors, the NHS advises drinking more, and it helps to spread drinks across the day. People who have been told to limit fluids, for example because of heart or kidney failure, should follow their own doctor’s advice.
Practical habits for summer, work, sport and travel
- Carry a refillable water bottle and drink before you feel thirsty, as NIOSH advises for workers in heat.
- Drink before, during and after exercise, and choose cooler times of day for outdoor activity where you can.
- Limit fizzy, caffeinated and alcoholic drinks, which the NHS advises stone formers to avoid in large amounts.
- Keep salt low: the NHS advises adults to have less than 6g of salt a day. Do not take salt tablets unless a doctor has told you to; NIOSH warns they can cause nausea and vomiting, which worsens dehydration.
- When travelling, plan drinks and toilet stops, and keep water with you on flights and long drives.
For food advice, see the stone prevention diet. Fasting has its own challenges, covered in kidney stones and Ramadan.
When it is urgent
The NHS advises getting urgent medical help if you think you have kidney stones and are in severe pain, or have a high temperature or feel hot, cold or shivery. Seek emergency care straight away if you have:
- severe pain in the side, back or groin that does not settle
- fever or shivering together with stone pain, which can mean infection behind a blocked kidney
- vomiting that stops you keeping fluids down
- very little or no urine
- signs of serious dehydration that the NHS lists as needing immediate care, such as confusion, or skin, lips or tongue that look pale, grey, blue or blotchy, or skin that feels cold
Read more about kidney infection.
How a stone is diagnosed after a hot spell
If you develop stone symptoms after a period of heat, the doctor will ask about your pain, fluid intake and work or exercise, and examine you. A urine test checks for blood and infection, and blood tests check kidney function. Imaging, usually ultrasound or a CT scan, shows the stone’s size and position and whether it is blocking urine flow.
If you have had more than one stone, a stone analysis and urine collection can show why stones keep forming and how much urine you actually pass in a day. That information is used to set a realistic drinking target for your climate and lifestyle. The stone treatment page explains the options if a stone does not pass, and the centre’s urologists can assess your stone and your risk of future stones.
Frequently asked questions
Do kidney stones happen more in summer?
Research suggests so. A Children's Hospital of Philadelphia study, reported by ScienceDaily, found that kidney stone presentations rose as daily temperatures climbed, with the effect peaking within 3 days of hot weather. Sweating without replacing fluid concentrates the urine, which helps crystals form.
How much water should I drink in hot weather to prevent kidney stones?
The NHS advises adults to drink 2.5 to 3 litres of water a day to help prevent stones, and the EAU guidelines aim for 2.0 to 2.5 litres of urine a day. In heat, outdoor work or sport you will usually need more, so use pale urine as your guide.
Can dehydration alone cause a kidney stone?
Dehydration on its own does not always cause a stone, but it concentrates the urine so minerals can crystallise more easily. People with other risk factors, such as a previous stone, certain diets or medical conditions, are more likely to form a stone when they are regularly short of fluid.
Are sports drinks better than water for preventing kidney stones?
The EAU guidelines name water as the preferred fluid for stone prevention. NIOSH notes that sports drinks are often unnecessary for replacing salts, because regular meals usually provide enough. Water is the simplest everyday choice.
What colour should my urine be in hot weather?
The NHS advises drinking enough during the day for your urine to be pale. Dark yellow, strong-smelling urine, or passing urine less often than usual, are signs of dehydration and mean you should drink more.
References
- Climate change may bring more kidney stones – ScienceDaily
- EAU Pocket Guidelines on Urolithiasis 2026
- Kidney stones – Prevention – NHS
- Dehydration – NHS
- Keeping Workers Hydrated and Cool Despite the Heat | NIOSH Science Bulletin | CDC
- Treatment & Prevention of Kidney Stones in Children – NIDDK
Book a consultation
Prof. Samir Al-Samarrai and Dr. Amer Mousa assess urological conditions at Prof. Al-Samarrai Medical Center, Dubai Healthcare City, and discuss the options that suit your case. Medical consultations are confidential.
Read more: Urologist in Dubai: doctors, services, insurance and booking
This information is for health education and does not replace a medical examination. See our medical content policy.
Medically reviewed by: Prof. Dr. Samir Ahmed Al-Samarrai, consultant urologist. Review date: .
About the doctor
Prof. Dr. Samir Ahmed Al-Samarrai, consultant urologist. He studied medicine at the universities of Heidelberg and Johannes Gutenberg in Germany and graduated with distinction, earned his doctorate (PhD) with a research thesis in 1980, and on 23 August 1978 received his specialist certificate in the treatment and surgery of male urological diseases from the Free University of Berlin, at its medical school hospital, under the specialist regulations of the Berlin Chamber of Physicians.
Clinic: Prof. Al-Samarrai Medical Center, Al Razi Medical Complex 64, Building D, 2nd floor, No. 2018, Dubai Healthcare City, Dubai. MOHAP licence: ZGU3I12X-291225.
This article is for health education and does not replace a consultation with a doctor. Last updated: 6 November 2026.
How we write and review our content: medical content policy