Wisconsin lakeshore counties are under an air quality advisory until 11 p.m. Saturday

Eight lakeshore Wisconsin counties are under an air quality advisory for potentially unhealthy ozone levels until 11 p.m. Saturday. Children, older adults, people working outside and those with lung or heart ailments are encouraged to take precautions for their health, according to the Wisconsin Department of Natural Resources.

Here's what to know:

Ozone advisory issued for eight counties, including Door, Milwaukee, Racine

The DNR issued an ozone advisory from 2 to 11 p.m. in Milwaukee, Kenosha, Racine, Ozaukee, Sheboygan, Manitowoc, Kewaunee and Door counties.

The DNR has advised that the air quality in all eight counties may reach the "Unhealthy for Sensitive Groups" level before the warning subsides.

"People with lung ailments (such as asthma), heart disease, children, older adults, and people who are active outdoors (including outdoor workers) should reduce prolonged or heavy outdoor exertion," said a news release from the DNR.

How should people in sensitive groups take precautions during the air quality advisory in Wisconsin lakeshore counties?

It's OK for people in the groups sensitive to the air quality at this level to be active outdoors, but take more breaks, the National Weather Service advises . Be sure to watch for symptoms such as coughing or shortness of breath.

People with asthma are also advised to keep quick-relief medicine handy, according to the NWS.

People with heart disease should contact their health care provider if they experience symptoms such as palpitations, shortness of breath or unusual fatigue. That may indicate a serious problem, the NWS said.

More: Summer prepares for a resurgence, with Southeastern Wisconsin temperatures climbing into the 90s

What is the Air Quality Index in Southeastern Wisconsin?

The Air Quality Index is broken into six colored categories on a 0-500 scale, and when readings get above 100, air quality becomes unhealthy for certain groups, according to a previous Journal Sentinel report . AN AQI level between 101 and 150 is in the "Unhealthy for Sensitive Groups" category.

Shortly after 3: 20 p.m., Milwaukee, Racine and Kenosha counties had all reached that level. Milwaukee County was at an AQI level of 105, Racine was at 118 and Kenosha had reached 119, according to the Wisconsin Air Quality Monitoring Data map.

The other counties were at "Moderate" and "Good" levels at about the same time, according to the DNR map. However, they remain under an advisory as the potential remains for readings to rise. Ozaukee reached an AQI level of 86, and Sheboygan was at 87, the map showed.

Contact the reporter bfogarty@gannett.com .

This article originally appeared on Milwaukee Journal Sentinel: Wisconsin lakeshore counties are under an air quality advisory until 11 p.m. Saturday