Heatstroke & Dehydration

Heatstroke, sometimes called sunstroke, is a life-threatening condition that usually results from prolonged exposure to high temperatures, and/or over-exertion in hot weather. Often accompanying—or resulting from—dehydration, heatstroke signals the failure of the body’s ability to control its temperature, allowing its core to reach 40 degrees Celcius (104 degrees Fahrenheit) or higher. The medical term for heatstroke is hyperthermia.

A person with heatstroke requires immediate emergency treatment as, untreated, the extreme body heat can quickly damage the brain, heart, kidneys and muscles. Existing asthma, emphysema, and other lung conditions can also be worsened by heat. The damage intensifies the longer medical treatment is delayed, increasing the risk of serious complications or death.

Symptoms of Heatstroke

Symptoms of heatstroke include the following:

  • A throbbing headache
  • Fainting
  • Dizziness, light-headedness
  • Nausea, vomiting
  • Flushed skin
  • Inability to sweat, despite the heat
  • Rapid breathing, often shallow
  • Racing heart rate
  • Muscle weakness and/or cramps
  • Confusion, slurred speech, agitation, seizures, staggering, or coma

Act Fast

If you suspect someone has heatstroke (or you are experiencing any of these symptoms and are alone), you must act fast, as a delay could be fatal. Immediately call 911 or drive the person to a hospital if one is close by. While waiting, carry or steer the person to a cooler area, under a tree if outdoors, or into a cooler building. Remove unnecessary clothing and cool the body any way you can, using cold compresses (for example a towel dipped in seawater). If you have access to a house where there is a shower or bath, or a garden hose if unable to gain access, run cold water over the person or fill the tub with cold water and immerse them. If available, place ice packs or cold, wet towels on the person’s head, neck, back, armpits and groin. (These areas have many superficial blood vessels which will help to cool the body.) Never use ice packs to cool a child, senior, or person with an existing medical condition unless advised to do so by a medical professional. It is vital that you attempt to cool a person suffering from heatstroke any way you can until medical help arrives.

Causes & Risk Factors

Although heatstroke is usually caused by prolonged exposure to high temperatures, or over-exertion in hot weather, certain behaviours can increase risk. These include failure to wear appropriate clothing (light clothing that covers the shoulders and a wide-brimmed hat), consuming alcohol, and not drinking enough water to replenish that lost through sweating.

People at greater risk of developing heatstroke include babies and young children, and elderly people. Babies and young children have an underdeveloped central nervous system (CNS) and the elderly often experience deterioration of the CNS­—making it difficult for both groups to adapt to extremes of temperature. Elderly people who live in hot apartments without air conditioning are at high risk for heatstroke.

While most people recognize that babies, children and animals should never be left in a car (even for a brief period with the windows cracked), sometimes the temptation proves greater than common sense. Never, ever leave a person or animal locked in a car in warm weather. The temperature in a car can rise 7 degrees C (over 20 degrees F) in just ten minutes.

Certain medications can also increase a person’s risk for heatstroke. These include diuretics, which cause water to be lost from the body; vasocontrictors, which narrow the blood vessels; beta blockers, which regulate blood pressure by blocking adrenalin; and tranquillizers or anticonvulsives, which may inhibit the perception of there being anything amiss.

Finally, be sure to drink lots of water and take regular breaks in the shade if you are engaged in physical activity during hot weather.

Dehydration

Close to three-quarters of the human body consists of water. For the average adult, this amounts to 40 litres. Every day, we breathe and sweat close to three litres of this water away, and lose another 1.5 litres to urination.

Many of us spend much of the time in a state of mild dehydration due to consuming too many diuretic drinks like colas, tea and coffee. Although this has the effect of slowing us down, in hot weather, water loss through sweating is accelerated, resulting in severe dehydration. This is a serious condition that requires medical attention.

Within the body, water serves a number of important functions including facilitating the function of body cells, supporting digestion and excretion, the circulation of blood and lymph, and maintenance of body temperature. Without adequate water, vital body functions shut down, which is why people can live a lot longer without food than without water.

Symptoms of Dehydration

Signs of being dehydrated include the following:

  • Nausea and weakness
  • Dizziness and confusion
  • Headache and/or leg cramps
  • Increased heart rate, palpitations
  • Reduced urinary output, bright yellow urine
  • Dry mouth and tongue

Immediate medical attention is required if you, or another person, are experiencing a fever over 39 degrees C (103 degrees F); have difficulty breathing; are fainting or having seizures; have chest or abdominal pain, or have had little or no urinary output in the past 12 hours.

Ensuring you drink enough water throughout the day is very important, particularly during warmer weather, and always before and during physical activity. Remember that alcohol accelerates dehydration, and drink two glasses of water for every alcoholic beverage consumed.

As with heatstroke, seniors and children are more likely to become dehydrated as they may not experience the sensation of thirst as obviously as younger adults. This is particularly true if they have diarrhea and/or are vomiting.

The solution for mild to moderate dehydration is to drink more water, and/or an electrolyte formula such as Hydralyte®.(Water alone will not replace the electrolytes lost through sweat.) Juice is not a good idea when diarrhea is present as it can worsen the condition.

Read other articles in our Spring-Summer 2020 volume of our Bettercare magazine here.

Sun Safety for the Outdoors


Gardeners, golfers, and other participants in outdoor sports often become the victims of too much sun and too little protection.

Applying sunscreen and reapplying it at regular intervals, is reasonably easy to remember when outdoors. Always apply 20 minutes or so before exposure, reapplying at two-hour intervals, and again after getting wet.

Reapplying sunscreen during being active outdoors is often overlooked. The fact that we sweat heavily during exercising, which dilutes the sun protection we have applied, spells double trouble.

Pointers for staying sun safe outdoors

  • Golfers: Choose a high SPF sunscreen (minimum SPF 30) and reapply after nine holes. Seek out shade whenever possible. Wear a broad-brimmed hat and make sure to protect your neck.
  • Runners, and cyclists: Choose sweat-resistant or water-resistant sunscreen and remember to reapply after heavy perspiration.
  • Gardeners: Ensure you garden before 11 am or after 3 pm to avoid sun exposure at its strongest. Wearing long pants and sleeves in dark colors and tightly woven fabrics can also protect from the sun’s rays. You can even consider sun-protection clothing to further block UV exposure.

Most people do not apply enough sunscreen to reach the level of SPF indicated on the packaging. For adequate protection, you should apply two to three tablespoons of sunscreen over your body (approximately one and a half shot glasses) and a teaspoon on your face before going outside.

Whichever sunscreen you choose, be sure that it provides protection against both UVB and UVA rays. (Most sunscreens that offer this protection will say broad spectrum on the packaging.) UVA light penetrates more deeply into the skin, contributing to the risk of skin cancers.

The high-pressure sunlamps used in tanning salons emit doses of UVA as much as 12 times that received from the sun. As a result, people who use tanning salons are significantly more likely to develop skin cancer. Research also suggests that first exposure to tanning beds during the teens or 20s increases lifetime melanoma risk by 75 per cent.

Staying Safe in the Sun

  • Be sure to check the Environment Canada UV Index, which is published in most daily newspapers alongside the weather forecast. On days when the UV Index reaches 3 or more (moderate), you need to be extra careful to protect your skin.
  • Avoid sun exposure between 11 am and 3 pm.
  • Seek shade whenever possible.
  • Wear a wide-brimmed sunhat and sunglasses.
  • Reapply your sunscreen frequently (at least every two hours and always after swimming or taking a dip).
  • Avoid tanning and tanning beds.
  • Examine your skin from head to toe monthly. Look for moles that have an irregular border, or are non-symmetrical; that are more than one shade or colour, or are greater than 6 mm in diameter. Also be aware of moles that change in size, shape or colour. Report any such changes to your doctor.

Read other articles in our Spring-Summer 2020 volume of our Bettercare magazine here.

Reminder: Widely-used medications can make skin vulnerable to sunlight, may cause severe sunburn or rashes

Before heading outdoors this summer, our pharmacists are reminding you to be aware of sun-sensitizing drugs. Widely-used over-the-counter and prescription medicationssuch as antibiotics, sulfa-containing medications, and acne treatmentscan make skin more vulnerable to sunlight, increasing the risk of sunburn, and in some cases, make the skin photosensitive. This photosensitivity can cause photoallergic or phototoxic reactions to the sun’s UV rays, in the form of painful and itchy rashes, or even blisters and sunburns.

Phototoxic reactions are the most common and result in a sunburn-like rash within minutes or hours of the medication interacting with UV rays. Meanwhile, photoallergic reactions can develop days after sun exposure. They occur when UV rays trigger chemical changes, resulting in the body reacting to the medication as if it is an allergen. Side effects include a red, itchy, scaly rash and in severe cases, blisters. Reactions are somewhat unpredictable and can be a one-time occurrence, or it can happen each time the drug is taken and sun exposure occurs.

Be Proactive About Sun Protection

Everyone should be proactive about protecting themselves from the sun, but for those on sun-sensitizing drugs, it’s even more critical. Wearing protective clothing and applying sunscreen regularly are two important measures. 

If you’re taking sun-sensitizing medications, you can also reduce your likelihood of a reaction by planning sun exposure for earlier or later in the day to avoid the sun’s rays when they are strongest.

For advice on sun safety and sun-sensitizing medications, visit us at any London Drugs location to speak with a pharmacist.

Sun Care 101: A Parents’ Guide to Sun Safety

It can be time-consuming (and maybe a little annoying) to apply protective sunscreen on you and your family members—especially if these people happen to be squealing kids, just waiting to get outside in the sunshine! We’ve got some great tricks and tips for easy (ish) sun care application that will help keep your family covered. Here’s our guide to sun safety for parents.

Rules for Parents

Plan on five minutes per body

You might be thinking, “That is completely nuts! Sunscreen doesn’t take that long.” You may be right, but many of us groan at the thought of applying sunscreen on our kids because we don’t plan enough time for it. After gathering up all the snacks, water bottles, extra clothes, towels, sand toys, and so on, we’re already leaving an hour later than we wanted to. At this point, we’re often not in a good head space to tackle a rushed sunscreen job, so we either lose our tempers, give up, or decide to apply upon arrival. None of these are ideal.

So, yes, allowing five minutes per person is over-planning, but if you budget this much time there is a better chance you’ll actually leave the house smiling (and maybe even have a toy shovel packed for each kid!).

Apply 20 to 30 minutes before going out

We know: what a pain! But experts say sunscreen takes 20-30 minutes to become effective. Good thing we’ve already budgeted our time at home! Plus, following this rule means slathering on sunscreen away from all of the playground distractions and blowing sand. You may even schedule time between pajamas and getting dressed for the beach–it’s easier to apply sunscreen when kids are changing clothes. Also, remember to reapply regularly, especially after hitting the pool or the ocean for a swim.

Think of sun protection like you would a car seat

Toddlers cry and fight, but you still buckle them into a car seat (forcibly, if necessary), right? Sun protection is the same: a necessity. It’s not one of those teachable moments where you let your child choose not to wear a raincoat and get uncomfortably wet. One blistery sunburn in childhood can increase the risk of melanoma by 50%. Safety trumps tantrums, and that’s that.

 

Tricks for Kids

A quick internet search yields loads of tricks for making sunscreen tolerable for kids. Here are a few of our favourites.

A blogger at Happily Ever Mom lists seven ways to speed up the slather. One of her great methods is to make it into a timed challenge she calls “The Countdown”. The Countdown challenges mom or dad to finish the job before getting to number 10. She advises that parents make sure they are in charge of the counting, so they can stretch the countdown if they need to.

Another good trick is a game called “What’s Missing?” Apply everywhere but the nose, or one arm, and let your kid guess which body part still needs lotion. This gives your child the all-important power to point out mom or dad’s “mistake.”

Alternatively, you could give your child a sponge paintbrush and put her in charge of everyone’s sunscreen, like the girl in this video. It’s messy, but it works. And maybe their enthusiasm will solve this doctor’s number one complaint: that parents don’t apply enough lotion.

 

Sun Safety while Solo

Remember back before you had kids, when you took a book to the beach, and the biggest problem you faced was trying to put sunscreen on your own back? Simpler times. If your kids hit the pool as soon as you get there, and you don’t have help for your own sun care, we’ve got you covered there too. Here are a few hilarious, but strangely practical tips for applying sunscreen to your own hard-to-reach places. The toilet brush isn’t for everyone, but maybe a spatula or paint roller could do the trick.


As you gear up to take on the summer sun, set challenging, yet realistic goals. Try to finish the application process without losing your temper, and work on getting through a whole summer without a sunburn. You can do this!

Stay safe out there in the sunshine.