Ontario Summer Heat: Sick Notes for Heat-Related Illness
Ontario summers bring extreme heat events that can cause heat exhaustion and heat stroke. Learn when you need a sick note and your rights as a worker.
## Summer Heat and Worker Health in Ontario
Ontario summers regularly bring extreme heat events, with humidex values exceeding 40°C in southern Ontario.
## When Heat Illness Warrants a Sick Note
- Heat exhaustion requiring recovery time
- Heat stroke (medical emergency — seek immediate care)
- Dehydration affecting work performance
- Pre-existing conditions exacerbated by heat
- Medication interactions with heat exposure
## Outdoor Worker Protections
Ontario's Occupational Health and Safety Act requires employers to protect workers from heat stress. If protections are inadequate, you may have grounds for a WSIB claim.
## Vulnerable Workers
- Construction workers
- Landscapers and agricultural workers
- Warehouse workers without AC
- Delivery drivers
- Workers on medication affecting heat tolerance
## Getting Documentation
MedLetter provides within 6 hours sick notes from CPSO-registered physicians for heat-related illness.