Drowning associated with hypothermia and cardiopulmonary resuscitation has a very poor prognosis. We report two such cases, where impossible oxygenation due to severe pulmonary oedema was treated with extracorporeal membrane-oxygenation (ECMO). Following cardiac arrest, mild therapeutic hypothermia for 24h was maintained as recommended, but subsequent rewarming precipitated additional pulmonary oedema. Little is currently known about how long to maintain therapeutic hypothermia to optimize neurological outcome and suppress reperfusion injury. In our patients, therapeutic hypothermia during veno-venous ECMO-treatment was extended for up to 6 days. Both patients survived with no neurological sequelae. We speculate that prolonged hypothermia was not only neuroprotective, but also minimized reperfusion injury including pulmonary oedema. Extension of hypothermia for several days seems safe and feasible in selected cases.