Q: I will be attending an outdoor wedding in August with my 85-year-old mother. I’m worried about her being out in the heat all day. Would it be a good idea to have her drinking electrolyte drinks that day to help prevent dehydration or heat stroke?
Outdoor weddings and other summer activities are some of the highlights of the season, but spending several hours in the heat can increase the risk of heat-related illness. Seniors are particularly vulnerable because, as we age, our bodies become less efficient at regulating body temperature. Many common medical conditions and medications can further increase this risk. Fortunately, with a little planning, most cases of heat-related illness can be prevented.
Heat-related illness occurs on a spectrum. The mildest form is heat cramps, which are painful muscle cramps that develop during or after physical activity in the heat. If the body continues to lose fluids and is unable to cool itself, heat exhaustion can develop. Although it often follows physical activity, it can also occur during prolonged exposure to high temperatures, even at rest. Symptoms include heavy sweating, weakness, fatigue, dizziness, headache, nausea, muscle cramps, and a rapid heartbeat. Without prompt treatment, heat exhaustion can progress to heat stroke, which is a life-threatening medical emergency.
Unlike heat exhaustion, heat stroke occurs when the body’s natural cooling system fails and body temperature typically rises above 40°C. This can quickly damage vital organs and may be fatal if not treated immediately. Warning signs include confusion, difficulty speaking, unusual behaviour, seizures, or loss of consciousness. The skin is typically hot and flushed and may be either dry or still sweaty. Call 911 immediately while moving the person to a cool, shaded area, removing excess clothing, and cooling them with cold water, ice packs, cool wet towels, or fans until emergency responders arrive.
Heat and humidity often go hand in hand. Because the body cools itself by evaporating sweat, high humidity makes it harder to release excess heat. This is why even moderately hot days can become dangerous when humidity is high.
While anyone can develop heat stroke, those at highest risk include infants and young children, seniors, people with heart disease, kidney disease, diabetes or obesity, those who sweat very little, people consuming alcohol, and anyone taking certain medications.
Some medications can make it harder for the body to cope with extreme heat, particularly when several are taken together. Diuretics, such as furosemide (i.e. Lasix), increase fluid loss and can make dehydration more likely. SGLT2 inhibitors, including empagliflozin (Jardiance), dapagliflozin (Forxiga), and canagliflozin (Invokana), can also increase urination and fluid loss. Medications with anticholinergic effects, such as oxybutynin (e.g. Ditropan XL, generic brands) and diphenhydramine (e.g. Benadryl), may reduce sweating and interfere with the body’s ability to cool itself. Certain antidepressants, particularly tricyclic antidepressants such as amitriptyline (e.g. Elavil, generic brands); and antipsychotics such as olanzapine (e.g. Zyprexa, generic brands), quetiapine (e.g. Seroquel, generic brands), risperidone (e.g. Risperdal, generic brands), and several others may also impair sweating, temperature regulation or awareness of heat, increasing the risk of heat exhaustion or heat stroke. Opioids, including morphine (e.g., MS Contin, Kadian and generic brands), hydromorphone (e.g., Dilaudid, generic brands) and codeine (e.g. Tylenol No. 3, generic brands), may cause sedation or cognitive impairment. Other sedating medications including benzodiazepines such as lorazepam (e.g., Ativan, generic brands), clonazepam (e.g., Rivotril, generic brands) and diazepam (e.g., Valium, generic brands), as well as sleep medications such as zopiclone (e.g., Imovane, generic brands) and zolpidem (Sublinox, generic brands) may also reduce alertness, thirst perception and a person’s ability to recognize and respond to dangerous overheating.
For most people, drinking water regularly throughout the day is the best way to prevent dehydration. Electrolyte beverages are generally unnecessary unless you are sweating heavily for a prolonged period, participating in vigorous physical activity, or have lost significant amounts of fluid through vomiting or diarrhea. They are not a substitute for staying cool and drinking enough fluids. Many electrolyte drinks also contain significant amounts of sugar, sodium, or potassium and may not be appropriate for people with diabetes or certain heart or kidney conditions.
Since your outdoor wedding is a planned event, encourage your mother to drink water regularly in the days leading up to the wedding and throughout the day of the event. Seniors often have a reduced sensation of thirst, meaning they may not realize they are becoming dehydrated until it has already begun. Limit time in direct sunlight, take breaks in air-conditioned or shaded areas, and wear light-coloured, breathable clothing. A wide-brimmed hat, umbrella, handheld fan or cooling towel can also help reduce heat exposure.
Protecting your skin from sunburn with a broad-spectrum sunscreen is another important way to reduce the risk of heat-related illness. Sunburn damages the skin, making it more difficult for the body to release heat, while increasing fluid loss though the damaged skin and the risk of dehydration.
Watching for early signs such as dizziness, weakness, headache, nausea, or confusion can prevent heat exhaustion from progressing to heat stroke. Before attending any prolonged outdoor event, ask your pharmacist to review your medications and medical conditions. They can identify factors that may increase your risk of dehydration or heat-related illness and recommend the safest approach to hydration and medication management based on your individual health needs.