When it’s hot outside, do not wait until thirst sets in to drink water. — Zacharie Scheurer/dpa
It's hot outside ... like, really, really hot.
Yes, a miserable heat wave is roasting much of the world, exposing millions of people to surging temperatures and elevated risk of heat-related illnesses.
Hydration is key to preventing those illnesses, which include cramps, exhaustion and stroke.
That’s because proper hydration regulates our body temperature, supports brain function and keeps joints lubricated.
On days like these, those outdoors should be especially mindful.
But exactly how much water should we drink?
Should we supplement with sports drinks?
And is it possible to drink too much water?
Here’s how to stay healthy in these blistering temperatures.
Firstly, drink water... lots of water
In this heat, do not wait until thirst sets in to drink water, said Dr Troy Smurawa, director of paediatric sports medicine at Children’s Health Andrews Institute for Orthopedics and Sports Medicine in Plano, Texas, United States.
Children and adults alike need frequent water breaks to combat dehydration.
“Don’t rely on thirst as an indication of when to drink water,” said Dr Smurawa, who instead recommends a proactive approach.
Adults working or exercising outdoors should aim for an 8oz (230ml) cup of water every 15 to 20 minutes, the US Centers for Disease Control and Prevention recommends.
That translates to roughly a litre per hour, but drinking water at shorter intervals is more effective than drinking large amounts infrequently.
For children ages four to eight, Dr Smurawa recommends 7.5 cups of fluid per day.
For ages nine to 13, he suggests nine to 10 cups, and for ages 14 to 18, he suggests 10 to 14 cups of fluid.
Those recommendations increase with heat and exercise, though.
If exercising, particularly in this heat, children ages nine to 12 should drink 3-8oz (90-230ml) of water every 20 minutes.
Teenagers should drink 8-16oz (230-470ml) in 20 minutes.
”The more we sweat, the more we need to drink,” he said.
Replenishing fluids after exercising or working in the heat is critical.
Dr Smurawa said he recommends drinking roughly 24oz (700ml) of water within two hours of exercise.
Signs of dehydration
Water accounts for roughly 50% to 70% of our body mass.
Losing even 2% of that from sweating can cause headaches, fatigue, cramping, low
blood pressure, confusion and, in the most extreme cases, loss of consciousness, Dr Bethany Agusala, an assistant professor at UT Southwestern Medical Center, wrote in a piece about hydration.
But can we drink too much water?
It’s rare, but it is possible.
Consuming excessive amounts of water without sufficient electrolytes can cause an imbalance.
Electrolytes are essential minerals, like sodium, which help regulate the body’s fluids.
When we sweat, we lose our body’s sodium.
Symptoms of overhydration, which is called hyponatremia, include confusion, headaches, nausea, vomiting and seizures.
To avoid overhydration, Dr Smurawa recommends adding a drink with electrolytes, like a sports drink, after about one hour of drinking water during exercise.
Or he suggests simply adding a half teaspoon of salt to a 20oz (600ml) water bottle after drinking plain water.
Besides drinking water, there are also other ways to stay hydrated
Dr Agusala said 20% of our daily water intake should come from foods rather than drinks.
Water-rich foods include cucumbers, tomatoes, celery, watermelon, zucchini, strawberries, lettuce, peaches and yogurt. – dpa
