The COVID-19 pandemic has caused an unprecedented health crisis worldwide, with the numbers of infections and deaths worldwide multiplying alarmingly in a matter of weeks. Accordingly, governments have been forced to take drastic actions such as the confinement of the population and the suspension of face-to-face teaching. In Spain, due to the collapse of the health system the government has been forced to take a series of important measures such as requesting the voluntary incorporation of final-year nursing and medical students into the health system. The objective of the present work is to study, using a phenomenological qualitative approach, the perceptions of students in this exceptional actual situation. A total of 62 interviews were carried out with final-year nursing and medicine students from Jaime I University (Spain), with 85% reporting having voluntarily joined the health system for ethical and moral reasons. Results from the inductive analysis of the descriptions highlighted two main categories and a total of five sub-categories. The main feelings collected regarding mood were negative, represented by uncertainty, nervousness, and fear. This study provides a description of the perceptions of final-year nursing and medical students with respect to their immediate incorporation into a health system aggravated by a global crisis.