This afternoon heat index values will reach 105 to 108 degrees in many areas. Heat index values are forecast to increase further Saturday and Sunday. Residents are encouraged to take appropriate precautions to prevent heat related illnesses today through the weekend. Plan strenuous outdoor activities during the early morning or late evening. Drink plenty of water, wear light weight and light colored clothing, and take frequent breaks from the heat. Young children and pets should never be left unattended in parked vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.