Drilling in hot environments is becoming more and more common throughout the industry. The need to assure nowadays growing energy supply asks for intensive development of demanding oil and gas fields as well as investments in other energy sources like geothermal energy. Either way, both have in common, that high temperatures are frequently encountered during drilling and production operations, thus causing concerns for operations, tools, well integrity and safety. The scope of this work is to give a general understanding about the temperature development during drilling and to point out consequences for the involved operations. In the introduction an overview about the actual activities and demands for high temperature drilling applications is presented. Common implementations, such as in HP/HT fields and geothermal hot spots as well as future technologies like the Hot Dry Rock technology are described briefly. Thereafter, an outline is given about subsurface heat-flow and the according static temperature situation down-hole. Further a profound description about the development of the dynamic temperature profile during the hole-construction process is illustrated. In a second step the attempt is to determine the relation and the impact of the various interacting parameters, affecting the temperature development during the drilling process. Therefore, available data of a geothermal well drilled by DrillTec GUT GmbH was used and processed with the aid of a numerical simulator as well as an analytical method. Temperature profiles for the different operations were generated and compared to the actual sensor data, to verify the results. As a next step, parameter studies were conducted with both models, in order to get an overview of the impact and interaction of the single operational parameters. The results are discussed and further estimates are conducted. The deteriorating influence of excessive heat on materials such as electronics, polymers, fluids, cement and metal is discussed in an additional chapter. General limits for tools and components involved in the whole construction process are identified and tabulated. In view of the occasion DrillTec´s rigs were investigated for potential improvements and limits regarding high temperature. In a last step potential cost drivers for drilling operations in high temperature environments were evaluated and presented.