Staying Hydrated in Hot Weather – more than ‘8 glasses’

We’ve all heard that we need to drink 8 glasses of water a day, but is that true? How we know if we are properly hydrated? And does it have to be water, or can we drink something else?

The Myth of ‘8 Glasses’

While we’ve all heard we need to drink ‘8 glasses of water’ everyday, our water needs really depend on many factors, including our health, how active we are, and whether it’s hot or humid outside.

Why Water is Important

By weight, our body is about 60 % water and every system in our bodies depends on water to function properly. For example, water flushes toxins out of our kidneys and livers, carries nutrients to our cells and serves to keep the tissue in our ear, nose and throat tissues moist.

Lack of water can lead to dehydration; which results when we don’t have enough water to carry out normal functions. Even mild dehydration can drain our energy and make us tired. Severe dehydration can be very serious; resulting in hospitalization and in some cases, even death.

So How Much Water Do We Need?

Every day, we lose water as we exhale, perspire, and of course pass urine and have yes, we even lose water in our bowel movements. For our body to function properly, we need to replenish this water by consuming drinks and even foods that contain water.

So how much water does the average, healthy adult living in a temperate climate such as southern Canada or the northern USA, need?

The Adequate Intake (AI) of water for an adult man is roughly 3 liters (13 cups) and the AI for women is 2.2 liters (9 cups) of total beverages a day.

If we are sick and have a fever or it is hot and humid out, we need to drink even more. We also need to take in more fluid if we exercise strenuously and sweat, even more so if we work out when its hot.

A quick look at your lips in a mirror will let you know if you need to drink more! If you see vertical lines or crevices, you are already dehydrated.  If they are very deep and wrinkled — even more so! Cracked or peeling?  It’s not looking good.

Here are some indications of how much additional water (above the Adequate Intake mentioned just above) that you need to take in for different reasons;

Exercise; When we exercise, we need to take in an extra 400 to 600 milliliters (about 1.5 to 2.5 cups) of water for short workouts but intense exercise lasting more than an hour (for example, running a marathon) means we need to take in that much more to drink. During long workouts, it’s best to drink something that contains a little bit of sodium, as this will help replace sodium lost in sweat and reduce the chances of developing low sodium levels, which in itself, can be life-threatening. It’s also important to keep replacing fluids after you’re finished exercising.

Environment; Hot or humid weather can make us sweat and means we need to take in additional fluid. In the winter, overly heated indoor air can also cause us to lose moisture and being at high altitudes (greater than 8,200 feet / 2,500 meters may cause more rapid breathing and increased urination, which means we need to take in even more fluid.

Illnesses or health conditions; When we have fever, or are ill with vomiting or diarrhea, our body loses even more fluids. In these cases, we need to drink more water and sometimes it is helpful to drink oral rehydration solutions, such as Gatorade or Powerade. The reason homemade chicken soup works well is it often has sodium (salt) in it as well as sweet root vegetables such as carrots, onions and parsnips or parsley root. We also need to increase our fluid intake when we have bladder or urinary tract infections.There are also certain health conditions that require people to limit their intake of fluid, including heart failure and some types of kidney, liver and adrenal diseases.

Pregnancy or breast-feeding; Women who are pregnant or breast-feeding need additional fluids to stay hydrated. Pregnant women should aim to drink 2.3 liters (10 cups) of fluids daily and women who are breast-feeding should drink 3.1 liters (13 cups) of fluids per day.

Beyond the tap: Other sources of water

Although it’s a great idea to keep water within reach at all times, you don’t need to rely only on what you drink to meet your fluid needs. What you eat also provides a significant portion of your fluid needs. On average, food such as fruit and many vegetables such as cucumbers and tomatoes provides about 20% of total water intake.

In addition, beverages such as milk, juice and soup are mostly of water.

Remember though, while beer, wine and caffeinated beverages such as coffee, tea or cola or root beer contribute to fluid intake, they increase fluid loss. Water really is your best bet because it’s calorie-free, inexpensive and readily available.

Staying Properly Hydrated

Another way (in addition to the ‘lip-test’ above) to tell if you are drinking enough is by making sure you are urinating enough.

In general, we should produce about 1.5 liters (6.3 cups) or more of colorless or very light coloured urine a day, so if we aren’t, we should “up” our fluid intake.

To make sure you are drinking enough, here are a few tips

“¢ Drink a glass of water (250 ml / 8 oz) or other calorie-free or low-calorie beverage after each meal and between meals.

“¢ Drink water before, during and after exercise.

Is it possible to drink too much water?

Although it is not common, it is possible to drink too much water and when your kidneys are unable to excrete it, the electrolyte (mineral) content of our blood becomes diluted, resulting in low sodium levels in the blood. This is called hyponatremia and is a very serious condition. Endurance athletes, such as marathon runners who drink large amounts of water, are at higher risk of hyponatremia.

Flavoured Water

Sometimes we just want to drink something other than water, so rather than turning to commercial flavoured water, why not make your own? Here is a recipe for a wonderful refreshing drink that is commonly drunk throughout the Middle East, where it can be very hot and humid. It’s called “Lemonana“.

“Limonana” is a combination of the word for lemon (limon) and mint (nana) in Hebrew and is a lovely refreshing combination of these two ingredients, plus a touch of sweetness. Add a splash of rose water (available in Middle Eastern grocers) for a touch of Middle Eastern flavour!


Limonana 2










4 medium-sized lemons, washed and sliced thinly
2 lg sprigs of fresh mint leaves, washed and torn
3 Tbsp berry sugar
2 litres ice water or 2 cups ice cubes plus water
(optional) 1 tsp rose water [available in Middle Eastern groceries]

How to make

Dissolve berry sugar in 1/2 cup boiling water in the bottom of a 2 litre glass pitcher, stirring until clear.

Slice the lemons thinly and add to the pitcher.

Toss the torn mint leaves in.

Fill pitcher with 2 trays of ice cubes and cold filtered water.

Add the rose water, if you have it (or leave it out).

Pour into glasses and enjoy!

If you follow the above Limonana recipe, the result should look like the photo above.