“Cold Call” is outlined in Doug Lemov’s book Teach Like a Champion. The move involves calling on students whether they have their hands up or not. The technique has the advantages of keeping the pace of the class moving, increasing the number of students a teacher can call on and elevating the level of student engagement. To be clear, it is important to normalize the routine in your classroom so that the Cold Call does not become stressful. You can see the move in action and read more about it in the links below.
Doug Lemov annotates a teacher using the move here.
Kindergarten teacher Jennifer Shaffer explains the Cold Call and shows what it looks like in her classroom.
A 2nd grade example here.
You can read a thorough description of the Cold Call here.
Boyd County Public Schools summarizes all 49 Teach Like a Champion moves here, including the Cold Call.