I did this experiment using a thermal imaging camera (the MHS-5000) to look for changes in temperatures using a Cell phone. Note that after several minutes of using a cell phone, the right side of the head is slightly warmer than the left side. What is interesting is that the entire head became warmer by 2oC (3.9oF). It is likely that the internal structures (i.e., brain) not visible to the camera also warmed up. I don’t know what the physiological or medical implications of this temperature rise are but it does make one think.
A thermographic image is produced by surface temperature differences. The camera senses these temperatures and converts each (thermal) point into a point of color which corresponds to the point’s temperature. The temperature gradient follows a spectral pattern in which blue is cool and red is warm. Note that there is an increase of approximately 2oC (or 3.9oF) after 10 minutes on the cell phone. I sell no telephone related products and do use a cell phone (but whenever I can, I now use a device to distance the phone from me). I just thought this was too interesting not to share.