AQHI scale
- 1–3 Low
- Ideal air for outdoor activities
- 4–6 Moderate
- People at risk may want to ease off if they have symptoms
- 7–10 High
- People at risk should reduce strenuous activity outdoors
- 10+ Very high
- Everyone should cut back on strenuous activity outdoors
Environment and Climate Change Canada. People at risk: heart or lung conditions, children, older adults.