The child's health rests in the hands of his adult careers. There are many factors which constitute health such as: rational plan of daily routine, healthy diet, sleeping, going for walks, doing physical activities and hardening. In the week, a child spends most of its time in kindergarten or school. That is why, it is so significant that the teacher shows both correct attitude and willingness to learn about his or her own behaviour as well as his/her influence on his or her own health. The ways of strengthening the children's immunity depend mainly on teachers' knowledge about health hardening. Hardening can be defined as a system of treatments that constitute an integral part of physical education among children. Not only in kindergarten but also at home hardening is a powerful health remedy that reduces the incidence of cold diseases from 2 to 4 times. Hardening is not a cure for diseases, but a preventive treatment. A hardened person can easily bear not only heat and cold, but also violent changes in ambient temperature, which can lead to the weakening of the body's defenses. Hardening induces a general strengthening of the body. It also leads to the increase in the efficiency of the central nervous system, as well as to the normalization of metabolism and improvement of blood circulation. Hardening is a significant element of a healthy lifestyle among people of all ages. However, it is especially significant for children whose body has not yet developed the ability to react quickly and rapidly to violent environmental changes. Children overheat faster or undergo hypothermia. What is more, they are more sensitive to changes in air humidity, especially to its increase, or UV radiation. Children, who are hardened from childhood, are less likely to get sick and find it easier to adapt in kindergarten. In regard to the aforementioned reasons, research was undertaken in this area, implementing an innovative method of hardening through pro-health education and breathing exercises in two kindergartens in Poland as a pedagogical experiment. The aim of the research was to determine how daily breathing exercises "Strelnikowej" during pro-health education in kindergarten affected children's health (immunity). The research included 42 children aged 6 attending two kindergartens in Biala Podlaska, 22 of whom formed an experimental group and 20 children a control group. An introductory pro-health talk as well as health-hardening exercises were conducted with the use of "Strelnikowa" method in the experimental group for three months from October to December. At the same time, a pre-school documentation, which included information on the incidence of every child getting sick in the months of October, November and December, was analysed on the basis of the nursery attendance register. The results of the conducted research with the use of the pedagogical experiment confirmed that, after 3 months of pro-health education as well as hardening based on the method of daily breathing exercises performed in the kindergarten, there was a significant improvement in the health of the pupils. The research constitutes the first stage of pilot studies included in the project on "Hardening children aged 5-6 attending various types of kindergartens in the country and abroad", which aimed at implementing in the kindergartens in the country and abroad selected methods of hardening the body by conducting a series of trainings directed at teachers and children.
