Temperatures climbed past the 30 C mark in Waterloo-Wellington on Monday, with humidex values approaching 40.

The weather was hot enough that Environment Canada issued a heat warning for much of southern Ontario, warning of specific risks to certain groups of people – including those who work outdoors, seniors, children, and people without access to air condition.

At some locations, those last two groups overlap.

According to statistics provided by the Waterloo Region District School Board, 88 of the board’s 118 schools have air conditioning in at least part of the building, as do all of the board’s portables.

“When a school doesn’t have AC, we look for opportunities to install it during a renovation or maintenance on the school,” board spokesperson Lynsey Slupeiks said in an email.

At the Waterloo Catholic District School Board, 30 of the board’s 52 schools have full air conditioning, while a further 17 have partial coverage – leaving only five facilities with fans and open windows as their best respite from the heat.

For its part, the Upper Grand District School Board has 34 schools fully covered with air conditioning, 34 more with partial AC, and eight completely without.