Temperatures are expected to reach a high of 36 degrees in some places this week.
Whilst most of us will be pleased that the sun is out and temperatures are expected to exceed those in the South of France and Greece by Wednesday, caution should also be taken, with dehydration a real risk for many; particularly children and older people.
Please see some advice below on staying hydrated in the heat, from Dr Emma Derbyshire, adviser to the Natural Hydration Council.
“We are at the greatest risk of dehydration when we are too hot or too dry, have limited access to fluid, or need more fluid than usual – such as in warm or dry environments. With the exceptionally hot temperatures arriving this week, you should consume fluid at regular intervals throughout the day and evening, taking care to limit exposure to the hot sun, especially in the middle of the day.
“The NHS provides a useful recommendation that women should drink eight 200ml glasses and men should drink ten 200ml glasses of fluid per day . Water is one of the healthiest ways to hydrate, as it doesn’t contain sugar, calories or additives. Make sure you always have access to water, particularly when you’re out and about.”
Consequences of poor hydration
Studies show that losses of 2% or more of our body weight due to water restriction, heat and/or physical exertion can reduce cognitive (mental) performance . Some common symptoms of mild to moderate dehydration are given below  (the severity will vary depending upon our body size and the external temperature).
- Dark yellow or brown urine
- Delayed reaction times
- Dizziness or light-headedness
- Dry, sticky mouth
- Few or no tears when crying
- Increased thirst
- Muscle tiredness
- Reduced concentration
- Reduced urine output
- Reduced kidney function (Visit the Hydration & Kidney Health Fact Sheet)
- Sleepiness or tiredness – children may be less active than usual.
A recent survey indicated that only 4% of GPs believe their patients know how to hydrate properly and further research showing that 60% of the UK population drink one glass of water or less per day, there is a cause for concern that without the correct information, Brits may become dehydrated (particularly children and the elderly who are most at risk).
 NHS Choices: Water and drinks, April 2013.
 Ganio et al. Mild dehydration impairs cognitive performance and mood of men. British Journal of Nutrition 106(10),1535-1543, 2011. Armstrong, L.E. et al. Mild dehydration affects mood in healthy young women. Journal of Nutrition, vol. 142 no. 2, 382-388, February 1, 2012.
 Mayo Clinic (2015) Disease and Conditions: Dehydration. Available at: http://www.mayoclinic.org/diseases-conditions/dehydration/basics/symptoms/con-20030056
Please see below in addition, some top tips to staying hydrated when out and about.
5 top tips for healthy hydration:
- Make sure you always have access to water and drink it at regular intervals throughout the day.
- Bottled water is handy when you are at work or on the move.
- Remember that water-containing foods can contribute to your daily water intake, for example yoghurt, soups, stews, fruit and vegetables.
- Alcohol is dehydrating and should be balanced with plenty of non-alcoholic fluids, such as water.
- Remember to drink more when you exercise or spend time in hot environments.
- If you are attending sporting events, such as Wimbledon, make sure you have a bottle of water with you.