Being required to explosively eject from a fighter jet nine miles above the ground, and then parachute through a full blown thunderstorm, will make your day interesting indeed.
"As Rankin plunged toward the earth, licks of lightning darted through the massive, writhing storm cloud below him. Rankin had little attention to spare, however, given the disconcerting circumstances. The extreme cold in the upper atmosphere chilled his extremities, and the sudden change in air pressure had caused a vigorous nosebleed and an agonizing swelling in his abdomen. The discomfort was so extreme that he wondered whether the decompression effects would kill him before he reached the ground."