Measuring close proximity interactions in summer camps during the COVID-19 pandemic Elia Leoni, Giulia Cencetti, Gabriele Santin, Timofei Istomin, Davide Molteni, Gian Pietro Picco, Elisabetta Farella, Bruno Lepri and Amy L. Murphy EPJ Data Sci., 11 1 (2022) 5 Published online: 31 January 2022 DOI: 10.1140/epjds/s13688-022-00316-y