All of your personal electronic devices emit (laptops, cell phones, tablets etc.) Electromagnetic Radiation (EMR), or Electromagnetic Fields (EMF) that are comprised of Extremely Low Frequencies (ELF), Radio Frequencies (RF, Wi-fi, data etc.) and Thermal Radiation (heat), all of which are potentially harmful. Gamma Rays, X-Rays and UV are also types of EMR.
EMR has a high decay rate which means that most of the exposure is felt within a few inches and especially with direct contact. EMR can penetrate most natural and man made materials including wood, plastic, pillows, blankets, clothes etc.