MONTREAL -- Almost 900 people received medical attention as 10-kilometre and half-marathon events took place in Montreal under blazing heat, the event's medical co-ordinator said Sunday.

The shorter events were still held even after Montreal marathon organizers cancelled the full 42.2-kilometre marathon due to concerns over high heat and humidity.

Eddy Afram said the number of medical interventions was higher than usual, but still in line with the organizers' expectations given the temperature, which was expected to reach 30 C by Sunday afternoon.

In comparison, Afram said about 500 to 600 people are usually treated when temperatures are between 15 and 18 C.

In a phone interview, he said organizers made the right decision in cancelling the feature event, which would have required several more hours of running under increasingly hot temperatures.

"This was the best compromise and a good consolation race for those who couldn't do the marathon," he said.

He said most of the treatments were for heat stroke or common running injuries such as cramps and muscle strains.

Afram said organizers took numerous precautions to keep people safe, including increasing the number of medical staff, adding 18 more water stations and installing a spray system at the finish line.

The event also kicked off an hour early to avoid the hottest part of the day.

The region's emergency medical service also sent 10 ambulances and set up a command post to monitor the health of both runners and spectators.

A spokesman for Urgences-Sante said paramedics transported five people to hospital, while another 20 were taken to a medical clinic at the race site.