There’s not a lot of research on the effects of cell-phone use on children’s and teens’ health, the report acknowledges, but some studies have suggested that it may be associated with hearing loss, ringing in the ears, headaches and decreased well-being. Children who use cell phones will also have more years of exposure to RF energy over their lifetimes than people who started using them as adults, which leads some doctors to recommend added caution.
We couldn't find one legit EMF expert online or anywhere else that would recommend a radiation blocking case or anti-radiation case. Not the Environmental Health Trust or Magda Havas, or Joel Moskowitz, in fact his site, safeEMR cautions against scams and claims for radiation protection.  So if a so-called "EMF expert" is recommending any kind of anti-radiation case, they probably aren't that much of an expert. 
As a rule, modern medical equipment is well protected against exposure to radiowave radiation. Therefore, there is generally no need for concern regarding the effects of mobile phones on the normal function of the equipment. Nevertheless, the Ministry of Health recommends not to have a mobile phone in the immediate proximity (a distance of 30-50 cm from the portable medical equipment or from medical equipment implanted in the patient's body).
These stick on “blockers” don’t work. I am EHS and can tell you with certainty (because I feel the fields) that they are not blocking anything. You must use substantial materials like those used in faraday cages (silver and copper), which are now manufactured in materials and fabrics, or avoid EMF use period. Just look at military use for example. They are not using stick on blockers. Follow Ty’s advice for minimizing and avoiding EMF, and look up EMF blocking fabrics, building materials, etc… for the real blockers.

The Specific Absorption Rate test uses sophisticated instruments to measure the amount of radiation absorbed into the body, usually the head. At present, the generally recognized limit for absorbed electromagnetic energy is 1.6 watts per kilogram. All cell phones sold must be tested and have their compliance with this standard certified by their manufacturer. The electromagnetic fields from a cell phone depend upon the design of the cell phone and its antenna,how it operates, as well as how it is held and used. Tests conducted by the ABC show 20/20 has found that some of the country’s most popular cell phones can – depending on how they’re held – exceed the radiation limit. A cell phone’s antenna radiates in all directions. The health concern is about the radiation actually absorbed into the head, which is where cell phones are usually held. SAR tests conducted on the SAR Shield show that the product reduces SAR radiation by as much as 89%.
Released in 1993 as a joint creation of IBM and BellSouth, this was the first smartphone. A fax machine, a PDA, a pager and a mobile phone, the IBM Simon featured no physical keys, but used a touchscreen and optional stylus. Amazingly, it included applications such as games, email, a notepad, calculator, world clock, address book and a calendar. It only sold in the United States, for $899.
A carrier wave oscillates at 1900 megahertz (MHz) in most phones, which is mostly invisible to our biological tissue and doesn’t do damage. The information-carrying secondary wave necessary to interpret voice or data is the problem, says Dr. Carlo. That wave cycles in a hertz (Hz) range familiar to the body. Your heart, for example, beats at two cycles per second, or two Hz. Our bodies recognize the information-carrying wave as an “invader,” setting in place protective biochemical reactions that alter physiology and cause biological problems that include intracellular free-radical buildup, leakage in the blood-brain barrier, genetic damage, disruption of intercellular communication, and an increase in the risk of tumors. The health dangers of recognizing the signal, therefore, aren’t from direct damage, but rather are due to the biochemical responses in the cell.
Among the hundreds of smartphone cases available for iPhone and a bevy of popular Android phones, there are some that claim to reduce the amount of radiation your body absorbs when you have the handset close to your body. Pong Research is a US brand that offers a range of products fitting this description, as is Cellsafe, a company based in Victoria, Australia.
The following is an excerpt of a typical conclusion published in a scientific journal about the links between EMFs, cell phones and health: "Epidemiologic research shows a low degree of association, inconsistency and missing dose-effect relations. A biologic mechanism of action is still debatable. No harm to human health has been shown. Conclusion: There is no scientific basis as to the harmful effects of EMFs on human health."

Several studies that will provide more information are under way. Researchers from the Centre for Research in Environmental Epidemiology in Spain are conducting another international case–control study—Mobi-Kids—that will include 2000 young people (aged 10–24 years) with newly diagnosed brain tumors and 4000 healthy young people. The goal of the study is to learn more about risk factors for childhood brain tumors.
Nice quality vinyl bumper sticker is a not-so-gentle reminder to fellow motorists of the one of the many dangers of cellphone use: distraction! If you ever get the chance, you can also explain the other hazards as well: reaction time, increased permeability of the blood-brain barrier, and possibly brain tumors. Good for cars, trucks, bikes, skates and just about any other moving vehicle.
Wi-Fi radiation, which falls into the RF category, is similarly damaging – particularly for men who stand to suffer reproductive damage when RF-emitting devices such as laptops are positioned too closely to the groin area. Like with the issues caused by cell phone radiation, it’s best to keep laptop computers off your lap and away from your body as much as possible.
I recently had a tumor removed from my abdomen that was stage 1 cancer. I was shocked considering my lifestyle is very clean – organic, vegetarian, active, live on acreage in semi-countryside, happy, stress free, etc….I immediately realized where it came from. It was right where I would set my iPAD in my lap when I am not at a table. There is no way to know for certain, but it is the only thing that makes sense.
Consumers should utilize an air tube headset as a safer alternative to wired headsets or in-ear Bluetooth headsets, use the speaker feature and keep phones away from your body unless there is RF radiation shielding between the wireless device and cell phone users body.  When carrying a phone on your body it’s highly recommended to use either an RF Safe flip cover radiation shielded phone case or pocket shield to deflect excessive radiation away.

Perhaps more importantly, what types of radiation are causing, or likely to cause, or are suspected of causing, harm to humans? Is it the “harmonics” from the transmitter? Is it the RF from the circuitry? Is it the primary frequency on which the cell phone operates? This is important to understand. If the problem is the primary frequency on which the cell phone operates then forget the case and ditch the cell phone.
Cellsafe backs its claims by publishing independent test results on its site. These test reports are detailed, complex and confusing, but the results are available for you to interpret. For example, their tests found that an iPhone 4S produced a SAR of 1.069 W/kg on the 3G 2100Mhz frequency without a case, and 0.267 W/kg with a Cellsafe case. But what in the world does that actually mean? Is a SAR of 1 W/kg dangerous? Is a reduction to 0.267 W/kg actually better, or are we just splitting hairs?

The ultra thin (1mm) RadiCushion by Cellsafe slips into the cell phone case and redirects radiation away from the face of the phone. It's available in black or white but not recommended for use with aluminum or metallic cell phone cases. Test results show a SAR reduction of 96%. A slightly thicker (2mm) RadiCushion is available for iPad and iPad mini; it adheres to the back of the device and also provides SAR reductions of 96%. Visit their website for more information or watch this independent test which shows an 80% reduction and also compares it to the BlocSock:
Jump up ^ Gandhi, Om P.; Morgan, L. Lloyd; de Salles, Alvaro Augusto; Han, Yueh-Ying; Herberman, Ronald B.; Davis, Devra Lee (14 October 2011). "Exposure Limits: The underestimation of absorbed cell phone radiation, especially in children". Electromagnetic Biology and Medicine. 31 (1): 34–51. doi:10.3109/15368378.2011.622827. ISSN 1536-8378. Retrieved 2015-04-25.
SafeSleeve was founded in California by two Engineering graduates (University of Cal Poly San Luis Obispo) Cary and Alaey, with a desire to make a difference. They wanted to develop a product to help simplify, protect, and enhance the lives of their increasingly busy, tech dependent peers, family and friends. This is apparent in the highly efficient and useful, yet stylish designs and branding of SafeSleeve products. 
The CERENAT study, another case–control study conducted in multiple areas in France from 2004 to 2006 using data collected in face-to-face interviews using standardized questionnaires (18). This study found no association for either gliomas or meningiomas when comparing regular cell phone users with non-users. However, the heaviest users had significantly increased risks of both gliomas and meningiomas.