* WHAT...Dangerously hot conditions with heat index values from 100 to 112 degrees. * WHERE...Portions of central and north central South Dakota. * WHEN...Until 9 PM CDT /8 PM MDT/ Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. 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. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke. 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.