The term "temperature increase" refers to an elevation in the level or degree of heat within a specific environment, system or object. It generally means that the temperature has gone up from its previous state and is now higher than before. This could be due to various reasons such as exposure to direct sunlight, increased body warmth, or external heating sources. A temperature increase can have significant effects on physical processes within a system, including changes in the rate of chemical reactions, expansion of materials, and alterations in fluid dynamics. In biological systems, an increase in temperature can also affect metabolic rates, enzyme activity, and other physiological functions.