Steven "Steve" Rogers (Captain America)
In the beginning of World War 2, Steve Rogers was tested on for an experimental project called "Rebirth" that changed him into a super-soldier known as Captain America. After rescuing a young man from german military, Cap met a Special Canadian Resources man named Logan.
The two would later team up to liberate a P.O.W. camp in Poland, which they had to do without parachutes. They successfully freed all the prisoners, including a young Erik Lensherr. However, soon afterwards, Cap felt incredible pain. They later learned that "Rebirth" had a flaw for humans: a cellular breakdown, so Cap would die. Fearing they would force it on others, Cap and Logan snuck into "Rebirth"'s command center and destroyed the machine, unaware there was a backup.
Due to his heroic nature, S.H.I.E.L.D. placed him in a cryogenic tube to keep him alive until a cure could be found.