The International Summer School in Hydrogen & Fuel Cells Technology, organized by the University of Porto in the frame of HYLANTIC project took place virtually last June 16-18, 2021. Several members of HYLANTIC project attended the event. Alexandra Pinto, from U. Porto and president of the organizing committee, develired the talks “Hydrogen and Fuel Cells Fundamentals” and “Electrolysis Fundamentals”, while Carmen Rangel, from LNEG gave the lecture “Assesing Performance and Degradation in Fuel Cells and Electrolysers. Ex-situ and In-situ Investigations”. Moreover, Ulster University was in charge of the organization of the Safety Day, with the following talks: “Hydrogen safety in tunnels and similar confined spaces” by Dmitriy Makarov and “Tank-TPRD system with optimised diameter and TPRD-less tank” by Sergii Kashkarov. Finally, Volodymyr Shentov delivered the workshop “e-Laboratory of hydrogen safety”. Furthermore, Alfredo Ortiz, coordinator of HYLANTIC project, participated within Alexandra Pinto in the opening ceremony and also delivered the talk “Hylantic Project Outputs: Atlantic Network for Renewable Generation and Supply of Hydrogen to promote High Energy Efficiency”.