On-site treatment is preferred, followed by escalation therapy during evacuation once the patient's condition has stabilized. The procedures for the treatment of extremely severe HAPE are similar to those of severe HAPE, except for the treatment of complications. For patients with cerebral edema, the doses of dexamethasone and diuretics should be increased and airway maintenance is necessary. Hyperbaric oxygen treatment or oxygen inhalation through a ventilator is also recommended. Hypothermia is beneficial for the brain. For patients with serious heart failure, half or two-thirds of the recommended dose of digitalis should be administered in combination with an appropriate dose of a sedative. The daily dose of glucose should be <400 g to maintain low energy consumption and to promote osmotic diuresis. The treatments should be escalated during evacuation once the patient's condition has stabilized.