Manufacturers bury their warnings deep within their manuals:

“Keep iPhone at least 15 mm (5/8th inch) away from the body.”

On your iPhone: Go to Settings > General > About > Legal > RF Exposure

 “For body-worn operation, this phone has been tested and meets FCC RF exposure guidelines when used with an accessory that contains no metal and that positions the mobile device a minimum of 1.5cm from the body.”

Galaxy II – User Manual – Page 164

“Keep the BlackBerry device at least 0.98 in. (25 mm) from your body (including the abdomen of pregnant women and the lower abdomen of teenagers)”.

Torch 9800 – User Manual – Page 21

In a declaration submitted to Health Canada in June, 2014 by 50 Canadian MD’s, the following was stated: Out of sincere concern for the health of Canadians at all stages of life – from the developing fetus through childhood and into adulthood – we respectfully request that:  Health Canada develop and support strategies to raise awareness about microwave radiation impacts and to minimize prolonged exposure to microwave radiation in schools and other places where children are regularly exposed.”