* WHAT. Dangerously hot conditions with heat index values up to 100 possible. * WHERE. Portions of east central and southeast Indiana and central, south central, southwest, and west central Ohio. * WHEN. From Monday afternoon through Friday evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events, particularly for those working or participating in outdoor activities.

* WHAT. A prolonged period of dangerously hot conditions with heat index values near 100 degrees. * WHERE. Portions of east central and southeast Indiana and central, south central, southwest, and west central Ohio. * WHEN. From noon today to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 101 expected. * WHERE. Portions of east central Ohio, northwest, southwest, and western Pennsylvania, and northern and the northern panhandle of West Virginia. * WHEN. From 11 AM this morning to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values of 100 to 104 expected. * WHERE. Portions of east central Ohio, northwest, southwest, and western Pennsylvania, and northern and the northern panhandle of West Virginia. * WHEN. From 11 AM this morning to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. A prolonged period of dangerously hot conditions with heat index values near 100 degrees. * WHERE. Portions of east central and southeast Indiana and central, south central, southwest, and west central Ohio. * WHEN. From noon today to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 103 expected. * WHERE. Portions of northeast Kentucky, southeast Ohio, and much of central, western, and southwestern West Virginia. * WHEN. From 11 AM this morning to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Prolonged dangerously hot conditions with heat index values in excess of 100 degrees likely. * WHERE. Portions of north central, northeast, and northwest Ohio and northwest Pennsylvania. * WHEN. From 11 AM this morning to 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

The Miami Valley Regional Planning Commission and the Regional Air Pollution Control Agency have issued an Air Quality Alert for Montgomery, Miami, Greene, Clark, Preble and Darke counties in the Miami Valley Region, until midnight EDT tonight. Levels of ozone within the region may approach or exceed unhealthy standards. On Alert days, help reduce ozone by taking the following actions: * Carpool, if possible, bike, walk or take the bus instead of driving alone. * Refuel your vehicle after 8 pm. * Do not idle your vehicle, exhaust contributes to air pollution. * Mow your lawn in the evening hours and avoid the use of gas-powered lawn equipment. For additional actions and information, visit miamivalleyair.org or call 937-223-6323