Shivering

Shivering (also called shuddering) is a bodily function in response to early hypothermia or just feeling cold in warm-blooded animals. When the core body temperature drops, the shivering reflex is triggered to maintain homeostasis. Skeletal muscles begin to shake in small movements, creating warmth by expending energy. Shivering can also be a response to a fever, as a person may feel cold. During fever the hypothalamic set point for temperature is raised. The increased set point causes the body temperature to rise (pyrexia), but also makes the patient feel cold until the new set point is reached. Severe chills with violent shivering are called rigors. Rigors occur because the patient's body is shivering in a physiological attempt to increase body temperature to the new set point.

Located in the posterior hypothalamus near the wall of the third ventricle is an area called the primary motor center for shivering. This area is normally inhibited by signals from the heat center in the anterior hypothalamic-preoptic area but is excited by cold signals from the skin and spinal cord. Therefore, this center becomes activated when the body temperature falls even a fraction of a degree below a critical temperature level.

Mystery meat navigation

Mystery meat navigation (also known as MMN) is a disparaging term coined in 1998 by Vincent Flanders, author and designer of the website Web Pages That Suck, to describe a web page where the destination of the link is not visible until the user points their cursor at it. Such interfaces lack a user-centered design, emphasizing aesthetic appearance, white space, and the concealment of relevant information over basic practicality and functionality.

The epithet "mystery meat" refers to the meat products often served in American public school cafeterias whose forms have been so thoroughly reprocessed that their exact types can no longer be identified by their appearances: like them, the methods of MMN are clear to the producer but baffling to the consumer.

Flanders originally and temporarily described the phenomenon as Saturnic navigation in reference to the Saturn Corporation, whose company website epitomized this phenomenon. Flanders writes, "The typical form of MMN is represented by menus composed of unrevealing icons that are replaced with explicative text only when the mouse cursor hovers over them".