No, it is not harmful and actually can be stimulating for short periods of time. No problem with sitting on the bed to put on socks, talk to someone, etc. You just wouldn't want to be in it all night long. Dogs and cats are more tuned in to magnetism than humans. Indeed it is.
Many children have their own pads.
This is only an environmental restoration. It is not a treatment device. Many questions are asked about use with different types of beds. In general, the MagnetiCo Inner Power Sleep Pad can be used with any type of mattress that the pad can be placed under. The pad can be on a box spring, the floor, a platform, or slat base - whatever.