In early 2020, the Covid epidemic suddenly freezes humanity and empties cities. In Île-de-France, more than one million people choose to leave the metropolis to protect themselves. The immediate consequence of the health crisis, the urban exodus recalls the fragile links between city and health, between architecture and prophylaxis, between city and hospitality. It also opens a field of questions for the city of tomorrow: access to places of care and place of medicine; evolution of health facilities and management of all pathologies; aging of the population and accessibility of equipment or housing; urban mortality and burial place; health impacts of our metropolitan metabolisms and transformation of territories...