If the word "heading" is used, the use of "degrees" is redundant.
Some years ago on arrival into KPHX, I was flying an airplane with the number 210XX. On the same frequency was a 120XX, and a 210YY. We were alternately each being given altitudes and headings, such as "N210XX, turn left heading 120, descend and maintain FL210." "120XX, climb and maintain FL210 heading 210," and "210YY, descend and maintain one two thousand heading one two zero."
Very soon all the numbers began to blend, and predictably, someone in the mix mistook directions for one aircraft with those for another, and with hearing the same numbers over and over, it was very easy to hear an altitude and mistake it for a heading or visa versa, even for the wrong airplane. The use of "feet" and "flight level" and "degrees" in that case were useful supplements to "climb and maintain," "descend and maintain," and "turn left/right heading..."