 The Mac Senior Center, the Mac Inc. Senior Center, will be open today from 8 a.m. to 4.30. It's a cooling center for residents ages 55 and over. Mac located at 909 Progress Circle in Salisbury. Now in Dorchester County, the Cambridge Library and the Herlock Library serving as cooling stations. Today at the Cambridge Library, their hours 10 until 6. In Herlock today also, their hours 10 until 6.