Severe frostbite injury can result in significant lifelong disability and amputation. Various medicines, including intravenous vasodilators (prostaglandins/iloprost, pentoxifylline, buflomedil) along with thrombolytics (alteplase), have been described to counter tissue ischemia after rewarming, with poor quality of evidence. An in-class prostacyclin, epoprostenol, has similar pharmacodynamic properties to iloprost including vasodilation and platelet inhibition and has been used in peripheral tissue ischemia such as Raynaud's and scleroderma. In this trial, we will evaluate the effectiveness and safety of epoprostenol treatment for severe frostbite injury in addition to standard of care.