This thesis concerns the problematic of temperature rates in a luminiaire and their influence on light technical characteristics. The reason of heat creation in luminaires are light sources. Their basic division has been made and their energetic inputs have been shown in illustrations. An energy balance of a chosen light source has been shown - a lightbulb, a fluorescent lamp. From the point of heat tension of constructional components and therefore also from the point of safety we got to know technical standarts of heat attestations according to ČSN.

Another part of the project was concerning a heat transmision to the surround and its calculation. The most basic ways of sharing heat a their mathematical expressions have been shown. Some operation characterestics of light sources depending on temperature have been explained. Main part of the project is focused on practical part where a measuring unit for automatical light measurement has been created. New types of luminaires have been measured through and their warming-up characteristics have been created.