Grab that sunscreen and fill those ice cube trays because it is about to get uncomfortably hot in Toronto, with an Environment and Climate Change Canada (ECCC) heat warning issued for the city.

The heat warning for Toronto came on Thursday evening, with yesterday's warm, humid weather proving to have just been an appetizer for the giant blast of hot weather that will engulf the GTA this weekend.

Such warnings are issued by ECCC when it forecasts multiple consecutive days with max daytime temperatures of 31C or higher and minimum nighttime temperatures of 20C or warmer. They are also issued for multi-day spans where humidex values make temperatures feel at or above 40C.

A Heat Warning has been issued today for Toronto by Environment and Climate Change Canada, which is anticipated to last until Friday, August 20. The City’s Emergency Cooling Centres will open tomorrow, Friday, August 20 at 11 a.m. See news release: https://t.co/QasbKk5yug

— City of Toronto (@cityoftoronto) August 19, 2021

In response to the heat warning, the City of Toronto will be opening eight Emergency Cooling Centres this morning at 11 a.m.

If this number seems low, it is a product of the city's Heat Relief Strategy updates for 2020 and 2021 to include new public health measures. A handful of the facilities that were open in 2019 remain closed due to the pandemic.

Safety is strictly enforced at these remaining Cooling Centres, with rules like mandatory mask use, physical distancing, and frequent hand-washing.

As usual, the city is concentrating its Emergency Cooling Centres in lower-income neighbourhoods where residents may have limited access to air-conditioned spaces.

Cooling Centres will be open today at:

• East York Civic Centre – 850 Coxwell Ave.

• Etobicoke Civic Centre – 399 The West Mall

• Metro Hall – 55 John St.

• North York Civic Centre – 5100 Yonge St.

• Scarborough Civic Centre – 150 Borough Dr.

• Domenico Di Luca Community Centre – 25 Stanley Rd.

• Don Montgomery Community Centre – 2467 Eglinton Ave.

• Masaryk-Cowan Community Recreation Centre, 220 Cowan Ave.

All Cooling Centres will close at 7 p.m., except for Metro Hall, which remains open 24-hours during heat warnings.

The overflow of a growing homeless population — a community already facing numerous obstacles — into public spaces leads to further health concerns during heat warnings.

A pair of outreach teams from Streets to Homes and Fred Victor Keep Cool Project will perform additional wellness checks on encampments and other spaces where people living outside congregate.

The teams will direct people to the nearest Emergency Cooling Centre location and provide water well as other aid.

There are more ways to beat the heat, like the city's vast collection of indoor and outdoor pools and splash pads.

As with previous heat warnings, the regular recommendations include staying cool and hydrated, avoiding the sun, and protecting vulnerable people and pets.