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Dehydration and hot weather

The human body contains a high proportion of water, so when the temperature rises and the body tries to cool itself by sweating, dehydration can occur, particularly in children.

What is dehydration?

Dehydration is the loss of water and salts from the body. We need water to maintain our blood volume and blood pressure and to ensure our body functions properly. Along with water, the body also needs electrolytes, which are salts normally found in blood, other fluids, and cells.

Why do we need water?

The human body consists of nearly 60 per cent water; brain tissue is said to consist of about 85 per cent water. 

Although fluid loss occurs during hard physical work, even simple tasks like gardening, walking or riding a bike can result in a significant loss of fluid within a very short period. We can also lose a lot of fluid in hot or humid conditions.

Babies and small children feel the effects of heat sooner and more seriously than adults. Children in cars need special protection from heat as cars can heat up very quickly. A parked, locked car can reach dangerously high temperatures very quickly, even if the windows are open slightly. You should never leave a child in a parked car — your child can quickly become overheated and dehydrated, with potentially fatal consequences.

Stages of dehydration

The early stages of dehydration usually have no signs or symptoms, but can include dryness of the mouth and thirst. Other symptoms of early or mild dehydration may include:

• headache;
• dry skin;
• passing less urine than normal;
• tiredness;
• dizziness; and
• cramping in the arms and legs

As dehydration increases, signs may include:

• extreme thirst and parched mouth and tongue;
• rapid pulse;
• dark, yellow urine;
• little or no urination;
• sunken eyes;
• in infants, a sunken fontanelle (the soft spot on the top of the head);
• skin that has lost its elasticity and doesn’t quickly return to its normal position after being pinched;
• absence of tears when crying;
• irritability or drowsiness; and
• irrational behavior

If you are with someone, particularly a child or young person, who suddenly becomes dizzy, nauseated or weak during hot weather, get them indoors or in the shade. Replace lost fluids with water or an electrolyte solution and cool the person down with a tepid shower or sponge bath and by fanning air over their moist skin. Seek medical attention if the symptoms get worse or last for more than an hour.

If someone has dry, red skin, a fast pulse, looks confused or delirious, or feels very hot, that person is in extreme danger and you should seek medical attention immediately, as well as taking the steps outlined above.

During hot and humid weather, you are at higher risk of dehydration and heat-related illnesses, including cramps, heat exhaustion and heat stroke. In severe cases, dehydration and heat stroke can result in shock and even death.

How do I combat dehydration during hot weather?

Water should be given to counteract dehydration in hot or humid weather, regardless of your activity level. Drinking water helps lower your body temperature and replace the fluid you lose through sweating. It should be drunk before you get to the stage of feeling thirsty.

It’s best to remember that other drinks, such as soft drinks, coffee, or alcohol-containing beverages, are no substitute for water. Although they contain water, they also contain ingredients which are dehydrating.

Sports drinks contain carbohydrates and electrolytes and are useful if exercising in hot weather. Oral rehydration solutions such as Gastrolyte and Hydralyte are also suitable. They should be made up and given according to the manufacturer’s instructions. Children should be encouraged to drink water before, during and after exercising, especially if the weather is hot.

So-called ‘energy drinks’ contain caffeine or other stimulants, and are not an appropriate rehydration fluid. If in doubt, water is the preferred option in most cases.

Preventing dehydration during hot weather

It is recommended that during hot weather we should be drinking water even when not thirsty. You can tell if you are well hydrated if you do not feel thirsty and your urine is a dilute (clear) color.

Other things you can do to avoid dehydration during hot weather include:

• avoiding the sun in the middle of the day — exercise or do outdoor activities early in the morning or evening instead;
• wearing sunscreen and a hat that shades your head, neck, ears and face — sunburn stops your body from cooling itself down properly;
• wearing thin, loose clothing — this allows good airflow, which helps sweat evaporate; and
• avoiding dark clothing, as this absorbs more heat than light clothing

Last Reviewed: 5 September 2018 
myDr

 https://www.mydr.com.au/travel-health/dehydration-and-hot-weather

Colorado is a popular place for winter sports such as skiing, snowboarding, ice skating, and sledding. According to dripdrop.com, the body’s thirst response is diminished in cold weather (by up to 40 percent even when dehydrated). This happens because our blood vessels constrict when we’re cold to prevent blood from flowing freely to the extremities. (If you’ve ever had cold hands in winter, you know the feeling.) This enables the body to conserve heat by drawing more blood to its core.

But because of this, the body is fooled into thinking it’s properly hydrated, e.g. you don’t feel as thirsty  and your body doesn’t conserve water. Thus, in cold weather, athletes are less likely to drink water voluntarily, and additionally, their kidneys aren’t signaled by hormones to conserve water and urine production increases, a condition call cold-induced urine diuresis.

So diminished thirst response and increased urine production are two contributing factors. Yet, there are several others that can lead to winter dehydration, including:

• Wearing extra clothing. Heavy jackets, long underwear and other pieces of warm clothing help your body conserve heat. But the added weight is one factor that makes the body work between 10 and 40 percent harder. By working harder, the body produces more sweat, contributing to fluid loss.
• Increased respiratory fluid loss. In cold weather, we lose more fluids through respiratory water loss. For example, when you can see your own breath, that’s actually water vapor that your body is losing. The colder the temperature and the more intense the exercise, the more vapor you lose when you breathe.
• Sweat evaporates more quickly in cold air. We often think we aren’t sweating in cold, dry weather, because it tends to evaporate so quickly. This is another factor that can contribute to a diminished thirst response.

So whether you’re hitting the slopes or spending an afternoon cross-country skiing – don’t forget to hydrate!

Read the original story here.

The International Bottled Water Association (IBWA) reminds consumers that maintaining proper hydration throughout the winter months is just as important as during warmer weather, and this holiday season people can help highway  safety and reduce ‘morning after’ effects by turning to water – including bottled water –  in place of alcoholic drinks at parties and functions.

“Staying properly hydrated throughout the winter is something people often forget as the temperature drops,” says Chris Hogan, IBWA vice president of communications. “Bottled water is an ideal beverage choice during and after the holiday season, when the winter air is dryer and people don’t notice their own moisture loss as much as in the summer months.”

“The National Highway Safety Transportation Administration reports that one-third of all highway deaths in the United States are still the result of drinking and driving. That’s a problem that only becomes more acute during the holidays.  So, instead of alcoholic drinks, opt for reliable and refreshing bottled water and get where you’re going safely,” says Hogan.

Bottled water provides the perfect beverage choice for those who wish to avoid or moderate calories, caffeine, sugar, artificial colors or flavors, alcohol and other ingredients. Whether as a replacement for high-calorie beverages, or as an alternative to alcoholic drinks, for guests and designated drivers, bottled water offers consumers a refreshing, healthy, hydrating, and convenient beverage that provides consistent safety, quality and good taste.

“In addition to helping you stay properly hydrated in the winter, water also plays a critical role in making smart choices during holiday festivities,” says Hogan.

“And with the variety of types available – from spring and purified to mineral to sparking bottled water – consumers have many choices to suit their specific needs and occasions.  So, choose bottled water and stay hydrated, stay healthy, and stay safe.” 

Original story: http://www.bottledwater.org/drinking-water-helps-people-stay-hydrated-during-busy-holiday-season