Muscle temperature is the result of heat balance on a regional level. The rate of temperature change depends on muscle mass and on the initial temperature characteristic for the person. Energetic muscle activity leads to increasing muscle temperature in everybody who exercises. The goal of this research was to show how and by how many degrees the temperature of m. triceps surae changes by preforming as little as two exercises which activate the muscle. Based on collected data, the goal is to compare the results between sexes as well as in people who train in comparison to those who don’t, and to see if there’s a difference in initial temperature as well as in change of temperature between groups. There were 30 participants in the research who were all without health issues, aged 18 to 26 years. All the participants are the students of grade university study of physiotherapy on the Faculty of health studies in Rijeka. Thermo camera FLIR A615 was used to determine the temperature of m. triceps surae. Based on the results, we can see how by preforming as little as two exercises in less than two minutes we can increase the muscle temperature. It also shows that women have lower resting muscle temperature than men and that the temperature increases more in women than in men. Persons in training have higher resting muscle temperature but the change in their muscle temperature is lower than in persons who don’t train. This research proved that there is a difference in muscle temperature before and after exercise between sexes and that there is a difference in temperature of m. triceps surae of persons who train compared to persons who don’t.