Health officials across the Commonwealth are strongly advising people to keep themselves hydrated with water this weekend. High temperatures and humidity sap moisture from the body quickly and heat-related illness can come on fast. Among the outdoor activities to enjoy in Kentucky this weekend are the River Regatta tonight and tomorrow in Augusta and the Sun Valley Bluegrass festival at Jolly Park in Alexandria. BreyerFest, the annual celebration of horses at the Kentucky Horse Park, is underway in Lexington.