The intensity and demands of One-Course-At-A-Time apply to faculty members as well as students. Case in point is geology professor Ben Greenstein, who presented at an international coral reef conference that overlapped with his 3 1/2-week paleontology course.
Greenstein asked a colleague to take over for three days, send the class tests by FedEx, and e-mail the final research papers to him in Bali. Greenstein graded papers on the trip home. The day he got back he graded the final lab exam and turned in his grades in time.