Most people are not aware how wireless devices might affect their health. To discuss the hidden reason behind what might cause these side effects towards human health, it should be addressed in a technical manner. In the US, the frequency band is a public resource which is governed by the Federal Communication Commission. These Radio Frequency (RF) energy radio waves are a form of radiation that is under investigation for its effects on the human body. The spectrum that is allowed in the wireless communication ranges from 9KHz to 300GHz. The amount of RF energy absorbed by the human body is quantified by the use of SAR(Specific Absorption Rate) where the rate of radiation absorption is stated in W/kg (Watts per kilogram). The average absorption limit for the general population's whole-body SAR is 0.08 W/kg. To contrast with the risk of using wireless devices, let us put a microwave oven as an example to compare.  The normal microwave oven's operating frequency is at 2.4GHz which is akin to the daily Wi-Fi communication operating frequency. However, the power of the microwave oven can reach up to 1 Kilowatt but the power of Wi-Fi is maintain at 1 watt or below. As a result, many scientists around the world have started to debate and discuss the long term issues of using wireless communication which may cause the same effect of a food in an oven.
The potential effects of wireless communication are still under investigation as the common RF that is used to transmit signals are considered low e.g. a GSM hand phone has a peak of 2 watts. However, biological effects may be present resulting from the heating of body tissues by RF energy which is better known as the "thermal" effects. It has been known for many years that exposure to very high levels of RF radiation can be harmful due to the ability of the RF energy to rapidly heat biological tissue. Two areas of the body, the eyes and the testes, are particularly vulnerable to RF heating because of the relative lack of available blood flow to dissipate the excessive heat load.
According to WHO, the human body will absorb up to 5 times more of the signal from FM radio and television from base stations. The frequencies that are used in FM and TV broadcasting is consider low which is around 100MHz to 400 MHz and a person's height is just suitable to become an efficient receiving antenna.
The power of the RF field is the greatest when at the core of the source, and diminishes with respect to the distance. The measured RF when it is near to the base transmission station could be higher than the RF guidelines imposed by the international standard. One may be at a higher risk of suffering from thermal effects if living nearby base stations. Besides, if a human is exposed to wireless radiations in high field density for a long period of time, it may increase the body temperature to a maximum of 1 C. But, most of the Wi-Fis located in accessible areas are normally below the standards set.