Heat Advisory is in effect for the San Joaquin Valley, West Side Hills, Sierra Nevada foothills and the Lake Isabella area from 12 PM PDT Today until 9 PM PDT Monday evening. Heat sensitive people and those who are new to the area will be most prone to heat illness. Dehydration and prolonged exposure or strenuous physical activity outdoors during the hottest time of day could lead to heat exhaustion and/or heat stroke. If you have to be outside during the afternoon, wear sunscreen, drink plenty of water, and wear light colored, loose fitting clothing.