Premier Kathleen Wynne promises her government will co-operate with an investigation by Ontario's information and privacy commissioner into the deletion of computer hard drives by executives with Toronto's Pan Am Games.

Canadian Evan Dunfee overcame stifling heat and humidity to capture gold in the men's 20-kilometre race walk at the Pan American Games on Sunday.

Athletes and spectators at the Pan Am Games are being told to watch for signs of overheating as temperatures soar during the second weekend of the competition.