What’s the easiest way to get live video to a headset?

I need to get video from a camera to be viewable in a nearby headset. I just need regular video, not 180 or 360 degree views. Preferably it would be streamed wirelessly but could possibly do it wired with a long enough cord. I've seen drone racing pilots use VR headsets, but what is the best way to accomplish this without a drone?