As temperatures soar again this week in regions like southern Ontario, health officials are warning that extreme heat poses a heightened risk for individuals taking common prescription medications or using street drugs. According to Dr. Samir Gupta, a respirologist at the University of Toronto, certain medications can interfere with the body’s natural cooling mechanisms, significantly increasing the risk of heat-related illness or exhaustion.
Medications That Increase Heat Vulnerability
The rise in chronic health conditions means more people are taking daily medications that may inadvertently hinder the body’s ability to regulate temperature. Dr. Gupta explains that many common drugs have an “anticholinergic effect,” which inhibits the nervous system’s ability to signal sweat glands. Since sweating is the primary way humans dissipate heat, these medications can lead to dangerous overheating.
Common categories of medications that may increase heat sensitivity include:
- Mental Health Medications: Antidepressants can interfere with the brain’s heat regulation center and, in some cases, increase sweating, which accelerates dehydration.
- Cardiovascular Drugs: Beta blockers and aspirin can prevent blood vessels from dilating, limiting the body’s ability to radiate heat. Some blood pressure medications may also reduce thirst sensations, masking the early signs of dehydration.
- Diuretics: These medications reduce body fluid levels, making users more susceptible to dehydration when combined with heat-induced perspiration.
- Antihistamines: Often used for seasonal allergies, these can inhibit the body’s ability to produce sweat.
Pro Tip: Storage Matters
Dr. Gupta emphasizes that medications should be kept in cool, dry places. Extreme heat—such as being left in a car—can degrade drugs, rendering them ineffective. Insulin should be stored below 30 C, and Epipens should be kept below 25 C to ensure they function correctly.
The Intersection of Heat and Substance Use
Heat waves also create distinct dangers for people who use street drugs. Data from the Waterloo region and Windsor-Essex County Health Unit indicates a correlation between extreme heat and increased overdose incidents. Between June 28 and July 2, the Waterloo region reported 44 suspected overdoses and one death during the summer’s first heat wave.
Julie Kalbfleisch, a spokesperson for the Sanguen Health Centre, notes that heat can cause more adverse reactions to certain drugs. Because the unregulated drug supply is increasingly toxic—often containing substances like veterinary tranquilizers—users face compounded risks. “We know that heat can actually cause a more adverse reaction with certain drugs,” Kalbfleisch said. She urges the public to remain vigilant, as individuals experiencing distress in public spaces may be suffering from the combined effects of heat exhaustion and drug toxicity.
Recognizing Signs of Distress
When encountering someone who may be in medical distress, Kalbfleisch suggests a structured approach to assessment:
- Check Responsiveness: Shout to see if the person wakes up. If there is no response, use a physical stimulus like a trapezius squeeze or a collarbone rub.
- Observe Breathing: Watch for slow or ragged breathing, or gurgling sounds.
- Check Skin Tone: Look for blue or purple discoloration on the lips or fingernails, which can indicate they’re in distress.
Did you know?
Both prescription drugs and certain street substances can cause “photosensitivity.” This makes skin more susceptible to sunburns.
Frequently Asked Questions
Should I stop taking my medication during a heat wave?
No. Dr. Gupta stresses that patients should not stop their medications. If you are concerned about side effects, consult your doctor, who may adjust the dosage or frequency rather than stopping the treatment entirely.
What should I do if I rely on power-dependent medical equipment?
Heat waves can trigger power grid strain and outages. If you use devices like oxygen concentrators or nebulizers, Dr. Gupta advises creating a backup plan in advance of extreme weather events.
How can I identify if someone is overdosing or just sleeping?
If you cannot wake someone up with a loud voice or a gentle physical stimulus, it may be a medical emergency. Always announce your intention to call 911 and administer naloxone if you are trained to do so.
Have you or a loved one adjusted your health routine to manage the heat? Share your experiences in the comments below or subscribe to our newsletter for more updates on public health safety.