Environment Canada has issued a heat warning for the city of Hamilton for Tuesday.

The combination of heat and humidity as measured by the Humidex could make the weather feel near 40 degrees in the afternoon, the agency expects. Environment Canada issues heat warnings when temperature or humidity is high enough to cause a greater risk of heat stroke or heat exhaustion.

The hot and humid airmass's stay in the region should be short-lived. Meteorologists expect a cold front to sweep across the Golden Horseshoe and southwestern Ontario Tuesday night, bringing temperatures back to normal for the rest of the week.

Anyone can develop heat illnesses in extreme heat. Drink plenty of water before you feel thirsty to ward off dehydration.

According to Environment Canada, the risk of heat-related health impacts is greatest for:

  • older adults
  • infants and young children
  • people with chronic illnesses such as breathing difficulties, heart conditions or psychiatric illnesses
  • people who work in the heat
  • people who exercise in the heat
  • people without access to air conditioning and
  • homeless people