The cameras can rotate 360 degrees, and they follow the players' movements within Test Chambers. As well as its main video camera, the security camera appears to have a small device attached on the side, which possibly monitors infrared radiation from the body heat of living creatures. Not a single security camera is featured in any of the maintenance areas or observation rooms of Aperture Laboratories, and it is therefore unknown how, or even whether, GLaDOS can monitor Chell's movements during her escape. Her calls through the Speaker System do not strongly connote that she is able to monitor the escapee. Placing a linked portal underneath a camera will cause it to be detached, followed by a warning from GLaDOS, in which she refers to the camera as "testing apparatus".