What do fighter pilots wear?

 A G-suit, that automatically inflates during maneuvering to help the pilot keep blood from pooling in his/her lower extremities.

A helmet.

An oxygen mask with built-in microphone.

A parachute (if not integral to the aircraft itself) that includes a "lowering device" to help you get down from a height if you happen to land in trees.

(All of it's essential for them to be able to fly)