To regulate a number of processes in the body, there needs to first be recognition of current levels in order to respond in the appropriate way. For example there is a temperature "norm" (~36.9°C), if this level is detected to be too high by the hypothalamus, a corrective mechanism will be triggered to lower it, and if the level is detected to be too low, a corrective mechanism will be triggered to higher it. Positive feedback, on the other hand, is when a high level of something triggers the body to increase it even further.