This app is an Introductory handbook of Critical care medicine At Northern (IC@N) Hospital and provides a simple and practical guide to critical care (intensive care) medicine. The primary purposes of this app are education and advice for medical and nursing staff with limited experience in the specialty of critical care medicine.The information is based on a problem-oriented and practical approach. It assumes some medical knowledge, basic clinical experience, and above all common sense. It provides useful advice about common and important aspects of critical care medicine and trouble-shooting of common problems in critically-ill patients, but it is not intended to be exhaustive nor comprehensive. The guidelines in IC@N have been developed, trialled, and revised over several years by the medical and nursing staff at The Northern Hospital (Northern Health, Melbourne, Australia; www.nh.org.au).Our motto is: soins intensifs sans frontieres (critical care without borders). The skills of critical care medicine can be taken outside of the Intensive Care Ward (ICU, ITU) to all areas of health care with the intention of preventing and treating serious illness before it becomes irreversible. IC@N