* WHAT...For the Heat Advisory, hot temperatures of 90 to 100 expected. For the Extreme Heat Warning, dangerously hot conditions with temperatures of 95 to 105 expected. * WHERE...Interstate 5 Corridor and Western San Gabriel Mountains and Highway 14 Corridor. * WHEN...For the Heat Advisory, from 10 AM Thursday to 10 AM PDT Friday. For the Extreme Heat Warning, from 10 AM Friday to 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...Heat hazards may extend into next week for portions of the region. 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. Stay cool, stay hydrated, stay informed. Monitor the latest forecasts and warnings for updates. If you do not have air conditioning in your home or lack shelter, you can call 2 1 1 for assistance locating appropriate shelter from the heat.