(Portland, OR)  --  An Excessive Heat Warning from the National Weather Service goes into effect for western Oregon and Southwest Washington on Saturday morning and continues through 11 p.m. on Monday.  High temperatures will be 20 to 30 degrees above normal for late June and could break several records.  The extreme heat brings the risk of heat-related illnesses.  Temperatures will decline after Monday, but they'll still be 10 to 20 degrees above normal.