* WHAT...Heat index values up to 100. Overnight temperatures remaining warm in the lower 70s.

* WHERE...Portions of central, east central, south central, southeast, southwest, and west central Minnesota and northwest and west central Wisconsin.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat illnesses. Prolonged heat waves lead to cumulative heat stress for those who cannot adequately cool down and recover each night. Cumulative heat stress significantly increases the risk of heat exhaustion and heat stroke as time goes on.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes.

To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1. close

* WHAT...The Minnesota Pollution Control Agency has issued an Air Quality Alert for fine particles pollution. The Air Quality Index (AQI) is expected to reach the Red or Unhealthy category.

* WHERE...East central, central, west central, southeast, north central, and northwest Minnesota.

* WHEN...Until 11 AM CDT Friday.

* IMPACTS...Some members of the general public may experience health effects. Sensitive groups, such as people with lung disease (including asthma), heart disease, and children and older adults, may experience health effects.

* ADDITIONAL DETAILS...Very heavy smoke is expected across the Arrowhead today, as large wildfires continue to spread. Hot temperatures, when combined with the air pollution, will exacerbate health impacts. A frontal boundary will then spread heavy smoke further south this evening into Wednesday morning, as it moves across northern and central Minnesota. The onset of smoke will be rapid. This boundary eventually passes through the Twin Cities and into southeastern Minnesota on Wednesday or Wednesday evening, bringing heavy smoke even further south. Additional rounds of heavy smoke are possible from Thursday through Friday morning across the alert area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Sensitive groups, such as people with lung disease (including asthma), heart disease, and children and older adults, should avoid prolonged or heavy exertion. The general public should limit prolonged or heavy exertion.

Reduce or eliminate activities that contribute to air pollution, such as outdoor burning, and use of residential wood burning devices. Reduce vehicle trips and vehicle idling as much as possible.

Keep windows closed overnight to prevent smoke from getting indoors. close