Can the night vision device and/or infrared illuminator be harmful to a person in any way?
No night vision devices or a camera does not produce any harmful radiations for human body or skin. They have an IR light which is invisible to the human eye. They are the best way of night surveillance. I am having AXTON AT-6E PoE Infrared Illuminator, 850 nm for night surveillance. If you are looking something for night security I would suggest AXTON infrared illuminator.
http://www.axtontech.com/at-6e-megapixel-ip-infrared-illuminator-850-nm/