UPDATE: Today's Air Quality Alert continues through Saturday, the MDEQ announced this afternoon. 

With the mercury expected to top 101 degrees today and continued high humidity, the Michigan Dept. of Environmental Quality has extended Thursday's Air Quality Alert through Friday.

According to a statement issued Thursday, MDEQ officials expect increased levels of ozone and fine particulates to make the air unhealthy for sensitive groups.

People and businesses should avoid these activities on Air Action days:

• Refueling vehicles or topping off when refueling
• Using gasoline-powered lawn equipment
• Using charcoal lighting fluid

Everyone is encouraged to car pool, use their bicycles or walk, and delay or combine errands when possible. Active children and adults, and persons with respiratory diseases such as asthma, should limit prolonged outdoor exertion, the MDEQ advises.

Learn more on the Michigan Department of Environmental Quality webpage.

The National Weather Service (NWS) has issued an Excessive Heat Warning until 9 p.m. Friday for southeast Michigan, as high temperatures and humidity may drive heat index levels to 105-110.

The NWS advises scheduling any strenuous activities early in the day. To reduce the risk of heat-related illnesses while working outdoors, the NWS advises taking frequent breaks in shade or air conditioning, wearing light-colored clothing and drinking plenty of water. 

For more advice about handling the heat, read "Prepare for Hot Summer, Farmington Hills Emergency Preparedness Commission Says".