The medical officer of health has issued an extended heat warning for Sarnia-Lambton.
The warning will remain in effect until Wednesday when conditions are expected to ease.
We set a new record high again on Sunday. The mercury climbed to 32.3 C (90 F) at Chris Hadfield Airport, snapping the previous record high of 30.8 C (86 F) set in 2007.
The record for September 25 is 30.3 C (86 F), also set in 2007.
Lambton Public Health says residents should take precautions in the heat, limit your time spent outdoors and drink plenty of water.
While extreme heat can put everyone at risk from heat illnesses, health risks are greatest for older adults, infants and young children and people with chronic illnesses.
You're also advised to check on the elderly and those who are vulnerable to make sure they are staying cool.
There are cooling centre locations across Sarnia-Lambton. A list is available at lambtonhealth.on.ca