Introduction and objective:
Poland, similar to a large part of Europe, lies in the zone of moderate climate, and most of the data concerning climate originates from the observation of temperature. An increase in the mean air temperature will probably be more perceptible and, consequently, an increase in morbidity due to some infectious diseases is possible. The objective of the study is the presentation of an outline of the climate in Poland and Europe, and to demonstrate the relationship between the ongoing climatic changes and infectious diseases.

Brief description of the state the knowledge:
In moderate climate, the largest number of cases of respiratory diseases are recorded during the occurrence of cold, dry winters with low insolation. In the 21st century, climatic changes will probably become a serious health risk worldwide. Temperature, precipitation and humidity are important environmental factors affecting the pathogens. Some infectious diseases show a tendency towards seasonal cyclical patterns, which may be explained by the effect of climate. Despite difficulties in presenting the impact of climate on infectious diseases, progress takes place in assessment of the effect of disproportionate increase in winter temperatures, increased intensity and frequency of weather phenomena.

Summing up:
Climate changes are observed both in Europe and worldwide, and probably in some environments these changes will be more perceptible. Climate exerts an effect on the environment, host, and pathogens. Some infectious diseases are very sensitive to changes in climate, such as temperature and humidity. The consequences of climate change are difficult to assess, but also inevitable, and possibly climate change will become a serious threat to humans