The Covid-19 pandemic has dramatically drawn our attention to the central issue of hygiene and the possibility to bring school education outdoors and into natural settings. In fact, international pedagogic thought has focused on a ‘nature-deficit disorder’ in today’s children for some time (Louv, 2005), as well as the need to review the prevailing form of school settings, no longer privileging indoor locations but rather outdoor environments. This contribution aims to focus on the experiences of open-air schools which, from the early 20th century onwards, have fought the hygienic and medical battle against the tuberculosis «pandemic», aiming to rediscover nature and the outdoors as a privileged educational environment for primary school children. Widespread internationally, these experiences foster the rediscovery of the educational value of outdoor settings and nature in all its scientific and cultural aspects, and, precisely because of their open-air environment, they have been promoters of self-government, responsibility, co-education, collective discovery, within the framework of the spread of international pedagogic activism. In particular, using lesser-known archive source and more recent bibliographical references, the attention here focuses on open air schools set up and developed in Italy from the early 20th century, fully-fledged examples of international outdoor schools that go way beyond those which have been known until now. Finally, it will take a look at the key experiences and personalities who have promoted a renewed form of education through nature in open air schools in Italy.