Heat, Hydration and IV Drips: A Summer Guide for Ontario

Ontario summers can be surprisingly punishing. Humid heat waves, long days on patios and job sites, weekend tournaments and backyard projects all push the body to sweat more than it is used to. Staying ahead of fluid loss is one of the simplest ways to protect your energy and your health through July and August.

Short answer: in hot, humid weather, drink regularly before you feel thirsty, replace salt as well as water when you sweat heavily, and rest in the shade or air conditioning. An IV hydration drip can help healthy adults catch up after a hot day or event, but heat exhaustion that does not improve, and any sign of heat stroke, needs emergency care.

Why humidity makes heat harder

Your body cools itself by sweating, and the sweat cools you as it evaporates. When the air is humid, sweat evaporates slowly, so you keep sweating without cooling down as effectively. That is why a humid 30 degree day in Vaughan can feel more draining than a dry day at the same temperature, and why Environment Canada’s humidex readings are worth checking.

Who is most at risk

• Older adults, who feel thirst less strongly
• Young children
• People who work or exercise outdoors
• Anyone with heart, lung or kidney conditions
• People taking diuretics, some blood pressure medicines or some mental health medicines
• Anyone without air conditioning during a heat wave

Heat exhaustion versus heat stroke

Heat exhaustion

Signs include heavy sweating, cool and clammy skin, headache, nausea, dizziness, muscle cramps, weakness and a fast pulse. Move to a cool place, loosen clothing, sip water or an electrolyte drink and apply cool, wet cloths. If symptoms do not improve within an hour, or get worse, seek medical care.

Heat stroke

Heat stroke is a medical emergency. Signs include a very high body temperature, hot red skin that may be dry or damp, confusion, slurred speech, fainting or seizures. Call 911 and start cooling the person while you wait. A wellness clinic is never the right place for heat stroke.

How much should you drink in summer?

There is no single number that suits everyone, because body size, activity and sweat rate vary widely. Practical guides work better:

• Drink water regularly through the day, not only when thirsty.
• Check your urine. Pale yellow is the goal.
• Drink before, during and after outdoor activity.
• If you sweat heavily for more than an hour, add electrolytes or salty snacks. Replacing only water after heavy sweating can, in rare cases, dilute your blood sodium.
• Eat water-rich foods such as watermelon, cucumber, berries and soups.

For more on minerals, read our guide to electrolytes for athletes, which applies to anyone who sweats a lot.

Summer habits that help

• Plan outdoor work and exercise for early morning or evening.
• Wear light, loose, light-coloured clothing and a hat.
• Take breaks in shade or air conditioning.
• Limit alcohol on hot days, as it increases fluid loss.
• Check on older neighbours and relatives during heat warnings.

Where an IV hydration drip fits

For a healthy adult who feels drained after a hot weekend, a long outdoor shift or a summer tournament, an IV hydration drip can replace fluid and electrolytes efficiently while you rest in a cool, quiet lounge. It is a supportive option, not a treatment for heat illness. Every first drip at AuraWell starts with a health screen reviewed by a qualified practitioner, and a registered nurse places and monitors your IV.

If you are an athlete, see muscle cramps during exercise and our Performance and Recovery IV. For everyday hydration questions, read signs of dehydration in adults and IV hydration versus drinking water.

Medications that make heat harder to handle

Some common medicines change how the body manages heat or fluid. If you take any of these, ask your clinician or pharmacist for summer advice rather than stopping them:

• Diuretics and some blood pressure medicines
• Certain antidepressants and antipsychotic medicines
• Antihistamines and other drugs that reduce sweating
• Stimulants, including some ADHD medications
• Some diabetes medicines

Heat can also affect how some medicines are stored. Insulin, inhalers and test strips should not be left in a hot car.

Keeping cool at home, step by step

1. Watch the forecast. Plan around heat warnings, which are issued for York Region when hot, humid conditions are expected.
2. Block the sun early. Close blinds and curtains on sunny windows in the morning.
3. Find a cool place. If your home is not air conditioned, spend a few hours in a cooled space such as a library, community centre or mall.
4. Cool your body. A cool shower, damp cloths on the neck and a fan help.
5. Check on others. Call older relatives and neighbours who live alone, at least once a day during a heat wave.

Outdoor work and sport in the heat

People who work outdoors in Vaughan and Woodbridge, from construction to landscaping, and young athletes at summer camps and tournaments face heavy heat exposure. The body adapts to heat over one to two weeks, so the first hot days of the season carry more risk. Schedule heavy work or training for cooler hours, take shade breaks, and replace both fluid and salt during long sweaty sessions. Our guide to muscle recovery after training covers what helps afterwards. If you have a heart, kidney or lung condition, our primary care team can help you plan a safer summer.

Planning ahead for a heat warning

Environment and Climate Change Canada issues heat warnings for York Region when daytime and overnight temperatures, or the humidex, stay high for at least two days. Those stretches are when heat illness becomes more common, especially for people who live alone or work outdoors. A little planning before summer starts makes a warning much easier to handle:

• Know where you can cool down. Libraries, community centres and shopping malls in Vaughan and Woodbridge are air conditioned and open to the public.
• Check in on older relatives and neighbours once or twice a day during a warning.
• Move errands, yard work and exercise to early morning or evening.
• Keep a few oral rehydration packets at home before the hot weather arrives.
• Ask your pharmacist or clinician whether any of your medications need extra care in the heat.

Anyone who becomes confused, stops sweating or faints in the heat needs emergency care through 911, not a clinic visit.

Worn out after a hot stretch? Learn about our Hydration IV Drip in Woodbridge or call 905-207-7000 to book at AuraWell Health, 4600 Hwy 7, Unit 105, Woodbridge, ON L4L 4Y7, serving Vaughan and Richmond Hill.