As soon as they buy a new cellphone, most people tend to ravenously rip the device from its wrapping, cast the accessories and directions aside and begin getting to know the gadget that will never leave their side. But within that discarded handbook lurks some important information. For instance, in the iPhone 5 manual it reads, “carry iPhone at least 10mm (about 0.39 inches) away from your body to ensure exposure levels [to radio frequency] remain at or below the as-tested levels.”