The Windsor-Essex County Health Unit is urging people to take it easy in this dangerous heat.
Humidex values are expected to hit 46 C (115 F) on Friday and Saturday.
Medical Officer of Health Dr. Wajid Ahmed said the best thing to do is to reduce outdoor activities between noon and 4 p.m. when the heat is at its peak. Ahmed said drinking plenty of water will also help people stay properly hydrated.
"When you're out there making sure you are hydrating yourself in the best possible way and don't spend too much time outdoors. Maybe take some breaks, come into the facility where you may have some air conditioning to help your body cool down a little bit," said Ahmed.
Ahmed said there are more people other than children and the elderly who are more susceptible to heat-related illnesses.
"People with mental health issues and people who either have cardiovascular disease or respiratory conditions, they are more vulnerable to heat-related conditions," he added.
Ahmed is urging hot factories and other employers who work either outside or in hot buildings to be mindful of labour laws and occupational health hazards to protect their workers.
Heat illness often starts with the swelling of the hands and feet, heat rash, and heat cramps. This can progress to heat exhaustion and heatstroke.
Symptoms of heat exhaustion are cool, moist, pale, flushed, or red skin, heavy sweating, headache, nausea or vomiting, dizziness, and exhaustion.
Heatstroke is having hot, red, and dry skin, changes in consciousness, rapid, weak pulse, rapid, shallow breathing, and body temperature may be very high.
The health unit and Environment Canada have issued a heat warning.