These are often experienced as static electric shocks due to the accumulation of charges on the human body. These effects happen for a frequency of EMF, which is below 100 kHz. The built up of charges on human body (eg: on hairs), gets excited and rises up. These accumulate and get discharged when any earthed metal is touched. Thus these may be termed as micro-shocks, where they directly does not affect any human being, but indirectly may cause loss of concentration or falls, trips etc.
Effects on Central Nervous System:
When the EMF frequency is less than 100 kHz, at times, the EMFs may interact with the central nervous system, thus causing interference in signals between the brain and the limbs. These could result in temporary or permanent loss in movement of limbs, visual process etc.
If the EMF frequencies are more than 100 kHz, then depending upon the frequency and the field strength, the body suffers from partial body or whole body heating. However, these does not happen in normal circumstances, unless any incidents/accidents in power plants or transformer stations. Sometimes, the body suffers overload of the thermoregulatory system resulting in heat stroke.
RF Shocks and Burns:
A typical example would be getting a shock from a RF charged capacitors or any conductors. Sometimes the shock would result in deep, very severe burns and may take time to heal.