Complex sentence: Left alone, he would overheat to the point where he would eventually die, resulting in the need for surgery and a fitting with a specially designed cooling suit filled with liquid nitrogen, complete with metal shunts installed in his skull to relieve himself of excess heat.
Split into simpler sentences: Left alone, he would overheat to the point where he would eventually die. As a result he was fitted with a special cooling suit filled with liquid nitrogen and had metal shunts installed in his skull to relieve himself of excess heat.