High sound levels can do serious permanent damage to your hearing! Don't stick your head in the bass speaker bins until your ears bleed! and if you think you have hearing damage do get yourself some medical advice as soon as you get home.
The smoke, fog and vapour from special effects units used on stage should not cause you any problems but strobe type lighting effects can cause epileptic fits in those who suffer from flicker sensitive epilepsy - venues will announce if they are using this so you will have time to get yourself away from the potential problem.
Lasers and Ultra Violet lighting are the two remaining effects that cause problems, so don't go looking directly into the beam of a laser or you may suffer eye damage and U.V. lighting can cause skin problems like sun burn.
The conditions listed here are very rare indeed and control systems are usually in place, the main control is keeping people at a safe distance and issuing warnings. Perhaps the most serious problem originates with strobe type lighting so take notice of any warnings given or displayed.
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