What are 7 trouble signs of a person with a heat illness in Canada?

Canadian summers are getting hotter, and more heat-related health problems are being seen. Whether you’re dealing with Ontario’s sticky humidity or the dry heat waves sweeping across the Prairies, knowing how to identify heat illness could save someone’s life.

This is especially important for older adults, children, and people who work outdoors. Let’s look at the 7 trouble signs of a person with a heat illness that suggest someone needs help.

1. Excessive sweating followed by dry skin 

Have you ever noticed someone sweating heavily and then suddenly their skin becomes dry? That’s a warning sign. Initially, bodies sweat like crazy to cool down—it’s the body’s natural cooling system.

The real trouble starts when someone stops sweating completely while still exposed to heat. When their previously damp skin becomes hot and dry to the touch, they’ve entered the danger zone. Their body’s cooling system has shut down.

2. Unusual confusion or disorientation

Summer heat affects the mind faster than most people believe. When someone’s core temperature rises, brain function is impacted before other symptoms appear. You might notice them struggling with simple tasks or seeming unusually irritable.

They might forget where they are, have trouble following your conversation, or not recognize people they know well. These changes may be subtle at first, but typically worsen quickly if they don’t cool down.

3. Rapid, shallow breathing and elevated heart rate

When a body is fighting to cool down, the heart and lungs speed up. You’ll notice how they breathe faster than normal, with breaths that seem shallow or labored. Their pulse will quicken and, in serious cases, you might see their heart pounding through their shirt.

This puts enormous strain on the heart, especially for Canadians with existing heart conditions. If you’re caring for someone with heart problems during the summers, pay special attention to these signs.

4. Intense headache and dizziness

“My head is pounding” is something you’ll often hear from someone developing heat illness. These aren’t ordinary headaches—they throb intensely, usually at the front of the head, as blood vessels in the brain expand due to rising body temperature.

Along with the headache comes that “wow, I need to sit down” feeling of dizziness. The person might tell you the world is spinning or that they feel unsteady. This happens because their body is sending blood to the skin for cooling, leaving less for the brain.

5. Nausea and vomiting

When heat stress hits hard, the stomach starts to complain. As the body focuses all its energy on cooling down, it diverts blood from the digestive system, typically leading to a sudden wave of nausea.

Someone dealing with heat illness might first mention feeling dizzy or having no appetite before things progress to actual vomiting. If someone starts throwing up after being in the heat, take it seriously—their body is sending a distress signal.

6. Muscle cramps and weakness

Those painful muscle spasms that appear during hot weather aren’t just annoying—they’re the body telling you something’s wrong. Heat-related cramps typically affect the legs, arms, or abdomen when too many electrolytes have been lost through sweating.

Beyond cramps, you might notice someone struggling with basic physical tasks. They might have trouble standing up, holding objects, or seem unusually weak. Their body is essentially redirecting energy from muscles to support cooling efforts.

7. Changes in skin color and temperature

Initially, heat exposure turns skin flushed and red as blood vessels expand to release heat. As things worsen, someone might take on a pale, ashen appearance.

In severe cases heading toward heat stroke, the skin becomes alarmingly hot—often above 40 °C—and might develop a reddish-purple tone as tiny blood vessels near the surface become damaged. While these changes are easier to spot on lighter skin, they occur regardless of skin tone.

Extreme heat isn’t something you should take lightly in Canada, especially as summers become increasingly intense. Recognizing the 7 trouble signs of a person with a heat illness can make the difference between a speedy recovery and a serious medical emergency.