This study investigated the effects of 2.45 GHz microwave radiation (exposed once or repeatedly – ten times in two weeks) on the cellular activation within the paraventricular nucleus of the hypothalamus, extracted from rat brains. High SAR triggered an increase of the c-Fos marker 90 min or 24 h after radiation, and low SAR resulted in c-Fos counts higher than in control rats after 24 h. Repeated irradiation at 3 W increased cellular activation of PVN by more than 100% compared to animals subjected to acute irradiation and to repeated non-radiated repeated session control animals. The results suggest that PVN is sensitive to 2.45 GHz microwave radiation at non-thermal SAR levels.
... our review shows that there is a substantial amount of studies which indicate that plants have experienced physiological or morphological changes due to radiofrequency radiation and show statistically significant changes for the short-term exposure duration (up to 13 weeks). In contrast, the results obtained from the long-term exposure studies (two publications using nine different exposures with exposure duration between 3 months to 6 years) support no physiological effects on plants when exposed to radiofrequency radiation from mobile phone radiation. This would bring a remarkable point to the discussion about the apparent absence of response to the long-term exposure that may be interpreted as adaptations. On the other hand, phenotypic plasticity of plants will permit them to change their structure and function; hence, plants to adapt to environmental change (Nicotra et al., 2010). Plants are naturally affected by environmental stresses due to their immobility. Plants could respond to the environmental factors of wind, rain, electric field and ultraviolet radiation and adjust its physiological condition to adapt to the change of environment (Braam and Davis, 1990; Braam et al., 1996; Mary and Braam, 1997) .... our previous findings (Halgamuge et al., 2015) indicate that the biological effects considerably relied on field strength and amplitude modulation of the applied field.
According to scientists involved in the process, the WHO may decide later this year to reconsider its categorization of the cancer risk posed by cell phones; the WHO itself told The Nation that before making any such decision, it will review the final report of the National Toxicology Program, a US government initiative. The results reported by the NTP in 2016 seem to strengthen the case for increasing the assessment of cell-phone radiation to a “probable” or even a “known” carcinogen. Whereas the WHO’s Interphone study compared the cell-phone usage of people who had contracted cancer with that of people who hadn’t, the NTP study exposed rats and mice to cell-phone radiation and observed whether the animals got sick.47

MATERIALS AND METHODS: Adult male Sprague-Dawley rats in the weight range of 230 to 260 g were divided into control, sham, Wi-Fi exposed groups. After long term exposure (4 h/day for 45 days) to Wi-Fi electromagnetic radiation, plasma levels of glucose and insulin during intraperitoneal glucose tolerance test were measured. Islet insulin secretion and content, lipid peroxidation and antioxidant status in pancreas of rats were determined.

Add Negative Ions: Exposure to WiFi can result in the build-up of positive ions that can have negative effects on our bodies. We can neutralize this by adding negative ions to our lifestyle, negative ions are highest after a thunderstorm and are present from the energy caused by the crashing waves on the beach. You can also try a negative ion generator.
“When symptoms are not addressed comprehensively– for example, using symptom amelioration without simultaneous elimination of exposure – cell membrane adverse reaction and damage continue to occur while the patient is assuming the cause of the problem has been eliminated. This lulls patients into a false sense of security, causing them to aggravate their exposures through the increased use of their wireless devices. When the damage reaches a critically harmful level, even the symptom amelioration can no longer be sustained by the damaged cells.”
Our studies point that WIFI is not completely safe at home near the animal or human body because it employ harmful radio waves. But it is safer compared to cellphone that it is close to our brain during communications. WIFI signals are everywhere. If you switched off your WiFi at night, you are still exposed to the WIFI signals coming in from neighbors but we have a significant reduction of the bioeffects of WIFI with distance from the router. Future investigations will focus on the long term bioeffects of WIFI placed at an important distance from the animal or the human.
Jump up ^ "Electromagnetic fields (EMF)". World Health Organization. Retrieved 2008-01-22. “Electromagnetic fields of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All populations are now exposed to varying degrees of EMF, and the levels will continue to increase as technology advances.”
The answer is yes, it can.  Will it always make people sick? No. Dr. George Carlo explains that there is most definitely a biological response to what he refers to as Information Carrying Radio Waves (ICRW-energy fields from many wireless devices).  When you're exposed to ICRW  a process of adaptation and compensation occurs in your body.  He has a great program that can help people adapt. 
If you’re one of the millions who missed the WHO’s news then it’s likely you also missed the fine print in Apple’s official iPhone User Guide. The part that states cell phones should be kept “5mm away from your body to ensure exposure levels remain at or below” Standard Absorption Rate (SAR). In plain language, cell phones should be at least 5mm away from you at all times, dammit.
Because of this physical law, even if  holding a Wi-Fi router directly against your forehead was very dangerous (and, we assure you, it is not) working in your home office 45 feet away from the Wi-Fi router would not be dangerous simply because the microwave radiation of the already minuscule 1 watt Wi-Fi router would have radically decreased in intensity. When you factor in that the Wi-Fi radiation is already harmless, you see that there is no situation in which the Wi-Fi signal from your router, your laptop, your media center, or any other Wi-Fi device in your home could possibly hurt you.
I think it might be part of the problem with all these kids losing it in the last decade and a half. Just something to think about. Maybe they should start building “wifi free”restaurants and buildings. They have been warning people since before they even started using it on a commercial bases that wifi was going to have serious effects on the human body. There’s just so much of a “hey as long as it doesn’t bother me I don’t care” attitude. I mean think about it. Now I’m not saying this in a negative way but look at the turnaround in public opinion about gay marriage. I mean it went from a hotly debated topic to “ah well they ain’t hurting anybody so let them do what they want. Except in the red states and if you notice a lot of those states are lacking saturated wifi signals. Just something to think about
Nevertheless, a group of scientists got together in the mid-2000s, calling themselves the BioInitiative Working Group. This group, which largely consisted of wireless radiation researchers, has written a harsh reply as feedback to the reports claiming that posed no health risks.  The reply lists a wide range of health effects scientists at the European Commission have unfortunately either ignored or dismissed.