Unionized elementary school teachers in Ontario say this week's heat wave is taking a toll on students who are stuck in schools without air conditioning.
The Elementary Teachers' Federation of Ontario says the extreme temperatures affect children's ability to learn and can cause health issues.
The union is calling on the province to take steps to relieve the heat, which could include installing air conditioning systems or setting up cooling stations.
It says all schools should have a heat stress plan and a maximum indoor temperature limit after which they must take action, including shutting down for the day if necessary.
Cooler weather is expected later this week.