As the kids head back to school, a heat warning will be in place.

Environment Canada issued the heat alert Monday afternoon for all of southwestern Ontario, including Windsor and Essex.

High temperatures and humidex values are expected on Tuesday and will continue through Wednesday.

Temperatures will climb to the low 30s on Tuesday and Wednesday with humidex values reaching 40 to 42.

The humidex will continue into Thursday, Environment Canada says.

Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.

Officials remind people to drink plenty of liquids, especially water before you feel thirsty to decrease your risk of dehydration.

Frequently visit neighbours, friends and older family members, especially those who are chronically ill, to make sure that they are cool and hydrated.

Never leave people or pets in your care inside a parked vehicle or in direct sunlight.