Electromagnetic radiation of some modern devices in everyday human`s working and living environment could be very interesting for researching because of many publications according to influences of electromagnetic radiation on human health. Special place take mobile phones and laptops, as probably the most frequently used devices today. Do they present danger for human health if they used excessively? Does the temperature from mobile phone or laptop can adversely affect on health of their users?This work present interesting researches, measuring and simulations results according to electromagnetic radiation of mobile phones and laptops potential effects on their users, and also consists results of measuring near power transformer station.The great part of this work was resulted in authors Magistar of Technical science thesis: Electromagnetic field mobile communication frequencies distribution in human, at the Faculty of Occupational Safety, University of Nis, Serbia.