Do you suggest waiting if you have a head cold?

Yes I advise waiting especially if you are not in good health even allergies will adversely effect you and others experience the pressure from the wind tunnel would be very very uncomfortable with a head cold.

Out of consideration for others if you have a cold stay home.

Only if you don't have lack of energy. Once you're in the wind tunnel, you don't notice anything else but that tunnel. It might even clear you up lol.