The Importance of Keeping Hydrated in Hot Weather


Keeping yourself hydrated under hot weather conditions is very important to avoid heat-related illness. Sufficient hydration is even more important when performing physical activity in high temperatures, the more your body sweats, the more fluid you need to replace.  

The circulation in your body helps to eliminate heat, but when the air temperature rises above 90°F (32 C), the only way your body is able to cool down to avoid overheating is by sweating. If your body has not been provided with enough fluid to allow cooling by evaporation or sweating, it can run into serious health problems such as fainting, digestive problems and even death.

Serious dehydration can quickly lead to fatal collapse of the circulatory system because the heart and temperature control systems can’t eliminate the core heat of your body. Your body is a little furnace, all functions in your body require energy which in turn generates heat. If you haven't taken in enough fluids to sweat and cool down, your body core temperature will rise and begin to destroy tissues and organs. This can cause a significant risk of heat stroke. 

Why is it so important to stay hydrated?

Half of your body weight is made up of water. Your body depends on water for many vital functions. Every cell, tissue, and organ in your body needs water to work efficiently. Your body uses water to maintain its temperature, remove waste, and lubricate joints. Water is essential for good health.

Water can be lost from the body by going to the bathroom, by sweating especially in hot weather conditions and even breathing. Some conditions make your body lose water even faster, such as being physically active, when running a fever, vomiting or suffering from diarrhoea. In these conditions it is extremely important to replace the lost water from your body as soon as possible avoiding the risk of becoming dehydrated.

How do I know if I’m dehydrated?

Signs of dehydration include the following:

  • Little or no urine, or urine that is darker than usual
  • Dry mouth
  • Sleepiness or fatigue
  • Extreme thirst
  • Headache
  • Confusion
  • Dizziness or lightheaded feeling

Tips on How to Stay Hydrated

As summer temperatures hit, here are a number of important tips.

  • Drink enough water to prevent thirst.
  • Monitor hydration level by checking the colour of your urine. It should be pale yellow and not dark yellow, too smelly or cloudy. Dark colour indicates dehydration.
  • For short-duration (less than 60 minutes), low-to-moderate-intensity activity, water is a good choice to drink before, during and after exercise.
  • Any time you exercise in extreme heat or for more than one hour, supplement water with a sports drink that contains electrolytes with 6-8 % carbohydrates. This prevents "hyponatremia" (low blood sodium), which dilutes your blood and could also lead to serious impairment and death.
  • Begin exercise well-hydrated. Drink plenty of fluids every day and especially before and within the hour before, during and after your exercise session.
  • Avoid alcohol the day before and on the day of exercise. Avoid exercising with a hangover.
  • All fluids count towards your intake including tea, coffee, juices, milk and soups, excluding alcohol, which is extremely dehydrating. The amount of caffeine in tea and coffee does not discount the fluid in them, even if they have a slight diuretic effect, according to the most recent report by the National Research Council's Food and Nutrition Board.
  • Eat at least five cups of fruits and vegetables per day, these all contain various levels of water and the all-important nutrient potassium.
  • During exercise, for those who experience high sodium losses, eat salty foods in a pre-exercise meal or add an appropriate amount of salt to sports drinks consumed during exercise. Orange juice is high in potassium. Dilute juices, such as V-8 or orange juice, 50/50 with water so that the drinks are 6% carbohydrate solutions (the same as sports drinks), which will empty from your stomach quicker than 100% juice (juices are naturally 12% solutions), allowing the electrolytes and water to quickly reach your heart and organs.
  • Following strenuous exercise, you need more protein to build muscle, carbohydrates to refuel muscle, electrolytes to replenish what's lost in sweat, and fluids to help rehydrate the body. Low-fat chocolate milk is a perfect, natural replacement that fills those requirements.
  • For long hikes, when you'll need food, dried fruit and nut mixtures contain high amounts of potassium, sodium, protein, carbs and calories - though continue to drink plenty of water.
  • To determine your individualized need for fluid replacement: During heavy exercise, weigh yourself immediately before and after exercise. If you see an immediate loss of weight, you've lost valuable water. Drink 3 cups of fluid for every pound lost; use this figure to determine the amount of water (or sports drink) you'll need to drink before and during your next exercise session to prevent weight/water loss in the future.