Calgary Stampede, Osheaga and more: A doctor's tips on heat safety, hydration and substance control for summer festivals in Canada

Yahoo

04-07-2025

Between the Calgary Stampede, Ottawa Bluesfest and Osheaga in Montreal, festival season across Canada has officially kicked off. While many Canadians last year faced scorching hot temperatures that reached highs of 40 degrees Celsius, this year currently seems to be a bit cooler, with only a couple parts of the country under heat warnings.
As of July 4, Environment Canada has issued heat warnings for southeastern Manitoba, parts of western Ontario and most of southern Ontario, including the Greater Toronto Area. In these areas, Canadians can expect to see daytime high temperatures in the low 30s, with some parts feeling up to 40 degrees with humidity.
The rest of the country might not be under a heat warning, which should allow for a comfortable start to this year's Calgary Stampede, running from July 4 to 13. But since it's summer, Canadians should still anticipate more heat later this month and in August. As the season runs its course, it's probably a good idea to think about staying safe and hydrated if you plan to have fun under the sun.
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.
While dramatically high summer temperatures might be a cause for concern, does that mean you should be skipping these outdoor celebrations altogether? Not necessarily, but it's a good idea to be cautious about what your body can handle and what you should do to prevent heat-related health problems.
"People are preoccupied with what's happening and they don't want to leave, or there are crowded conditions and it's difficult to move around, and the heat can be intense," Dr. Mike Howlett, president of the Canadian Association of Emergency Physicians, told Yahoo Canada about summer festivals in 2024. "So, a couple of things are at issue."
The Dalhousie University associate professor said for one, people need to be aware of their hydration and they should drink fluids as they spend time outside during these festivals. Additionally, festivalgoers should be concerned about heat exposure, especially as temperatures rise in Canada due to climate change.
"While hydration is important, also the amount of heat exposure and the warming up of your body temperature past what it can manage is another issue," he noted. "They're related, but not identical."
One way Howlett suggested people avoid any possible health problems during summer festivals is by taking frequent breaks, particularly from "hostile" environments: "If you're finding it extensively hot and and humid, then finding shade, finding cool areas as well as having enough fluids to drink and the ability to cool off a little bit is important."
Moreover, Howlett recognized summer festivals are often events where people consume alcohol or drugs, but he warned people to stay safe while using such substances. For instance, intoxicants can sometimes make it easier for issues like heat exhaustion, heat stroke and dehydration to happen.
Older adults and younger children should also take higher precautions, since they likely don't have as much resilience to dehydration and heat than other people. Additionally, Howlett urged people who have underlying medical problems, such as diabetes, heart or lung disease, kidney problems or other health issues, should also be more careful about taking breaks and being hydrated.
Finally, he recommended people wear loose-fitting light clothing, use hats and apply sunscreen if they're planning on spending time at an outdoors festival: "It's better to make a plan where you're going to take breaks out of the sun, where you're going to have lots of fluids, use hats and if you have medical problems, be more careful and avoid substances that are intoxicants that lower your ability to pay attention to what's happening."
Glen Kenny, a University of Ottawa professor and director of the Human and Environmental Physiology Research Unit, previously told Yahoo Canada that heat is a "silent killer." Howlett reiterated that sentiment, noting heat-related health problems can easily "sneak up on people."
Howlett added that heat stroke is basically an extreme version of heat exhaustion, where "your body has totally lost its ability to control its core temperature." In that case, your temperature will rise dramatically, leading to serious ailments like coma or seizures.
Sun and heat-induced injury is a real thing, and it can sneak up on people.Dr. Mike Howlett
"For every 10 minutes that you're not treated, it increases your death rate," he warned. "So, it's extremely important not to get to that state in the first place. Before that happens, you want to pay attention to things like if you're excessively tired and really worn out and fatigued more than usual for yourself, if you're starting to get dizzy and lightheaded."
According to the Canadian Red Cross, heat-related health problems arise when someone is dehydrated — and they can happen to anyone who stays in the heat or under the sun for too long. There are key differences between heat exhaustion and heat stroke that everyone should recognize.
Signs and symptoms of heat exhaustion and heat stroke
Heat exhaustion
Heat stroke
Skin
Moist, warm
Dry, hot
Physical
Headache, weakness,
exhaustion, nausea,
vomiting, fainting
Seizures, coma,
severe headache
Mental
Anxiety, dizziness
Altered behaviour,
irritable, aggressive,
bizarre
Breathing
Normal
Rapid, shallow
"If those things are happening, you should not go back out until it's settled over, which is not an hour or two," Howlett said. "It's like two or three days before you should go back out again."
Moreover, the Canadian Red Cross indicated you should immediately call 9-1-1 if someone has heat exhaustion if they're nauseous, vomiting, fainting, dizzy and have anxiety. If they have heat stroke and present any of the listed symptoms, call emergency services.
While alcohol is a fluid, you don't want to make the mistake that it's keeping you hydrated: "Anything with alcohol in it will tend to dehydrate you," Howlett shared.
While consuming alcohol, the body releases an antidiuretic hormone called vasopressin, according to Cleveland Clinic. This hormone works with your kidneys to help balance your body's fluids. However, alcohol is also a diuretic, which means it increases your need to urinate and, in turn, lose fluid.
The best way to counteract this is to stay on top of how much water you're drinking. While a common recommendation is to drink around eight glasses of water a day, the actual required amount of water someone should drink daily depends on the person.
While drinking alcohol, Cleveland Clinic dietitian Julia Zumpano suggested drinking eight to 12 ounces of water for every alcoholic beverage you consume. That will help slow your alcohol intake and mitigate the effects of the next morning's hangover.
When it comes to drugs, there are some that simply don't mix well with the sun. Howlett shared substances like ecstasy, cocaine or others within the amphetamines group can cause their own heat-related health problems. For one, he said it's possible they can cause a heat-related injury even without being in a hot environment. Moreover, they can make people become more active than they usually are, causing their body temperature to increase.
Other substances that might alter your cognition could present other issues. For instance, some might make you more drowsy or less oriented than usual, possibly causing you to fall asleep or remain under the sun for longer than you normally would.
While recreational drugs might be one concern, there are some medications that might also impact someone's sensitivity to heat. According to New Brunswick Public Health, there are several medications you should modify how you take if you're spending time outside in the heat:
Common medications including some antihistamines (like Benadryl), over-the-counter sleeping pills and anti-diarrhea pills
Psychiatric drugs like chlorpromazine, thioridazine, perphenazine, fluphenazine and more
Anti-parkinson drugs like benztropine, biperiden, ethopropazine and more
Anti-depressants like amitriptyline, doxepine, clomipramine and more
There's no doubt summer festivals are exciting events that draw thousands of people in, but there are certain risks festivalgoers must be aware of before they head out in the sun for the day. During Osheaga 2023 at Montreal's Parc Jean-Drapeau, paramedics responded to a dozen cases, four of which required hospitalization, according to the Canadian Press.
Just be aware to prevent a heat-induced or dehydration-induced injury. If people will take those precautions, then there's probably a lot less risk.Dr. Mike Howlett
Howlett noted even though someone might be young and healthy, they shouldn't automatically believe they're immune to heat-related health problems. Still, he said festivals with prolonged days or multi-day events likely aren't the best places to bring young children or seniors. Either way, he urged people to practice "common sense things" like not leaving your children in unshaded areas for long amounts of time and instead take precautions when heading outside.
"Dehydration, heat exhaustion, progressing to more serious states, it's a real thing. It's something you have to pay attention to," Howlett shared. "There's a reason why these major festivals hire ambulance services and paramedics to help. ... It's a big potential risk."