At the height of the COVID-19 crisis in the Netherlands a shortness of intensive care beds was looming. Dutch professional medical organizations asked a group of ethicists for assistance in drafting guidelines and criteria for selection of patients for intensive care (IC) treatment in case of absolute scarcity, when medical selection criteria would no longer suffice. This article describes the Dutch context, the process of drafting the advice and reflects on the role of ethicists and lessons learned. We argue that timely interaction between clinical and ethical expertise is necessary since the distinction between medical and non-medical considerations is not as clearcut as sometimes assumed. Furthermore, pragmatic considerations related to the specifics of an epidemic are of importance, for example, in relation to prioritizing health care workers. As a consequence, any protocol already present before the pandemic would need alterations to fit the current situation. The 'fair innings' criterion we proposed, rephrased as an argument of intergenerational solidarity, was considered reasonable by professionals as well as patient organizations. While it is desirable to draft ethical guidelines in 'peacetime' as a matter of pandemic preparedness, the pressure of an actual crisis facilitates decision-making, although it will also complicate a more democratic approach.