A heat alert will be in effect in the City of Ottawa from Saturday until next Tuesday, the first such alert this summer, which began nearly two months ago.

Heat alerts are issued by the city's medical officer of health, Dr. Isra Levy, whenever the humidex is at or about 36 for at least two consecutive days. (The humidex is not a temperature measurement per se but corresponds roughly to what the temperature would be in degrees C if both heat and humidity are taken into account.)

While the alert is in effect, the city advises drinking lots of fluids, getting access to air conditioning for at least two hours a day, wearing light-coloured clothing, including a hat and cooling down in the shade or in a pool.

It is also encouraging residents to check on those most vulnerable to the heat, such as elderly or chronically ill people who might have trouble accessing air conditioning, especially those above the second floor of highrise buildings. A public service announcement issued by the city also noted that medications such as anti-Parkinson's drugs and anti-depressants can make people more vulnerable to heat.