Karst geosystems are one of the most vulnerable to both natural and anthropogenic impacts. At the same time, karst sites and especially cave systems are very interesting and attract more and more tourists. The cave environment is specific and reacts in a particular way to global changes, which can increase the health hazard for visitors and especially for tour guides in show caves. It is mostly related to the concentrations of radon and CO2, which, according to the cave morphology and ventilation mode, can reach critical values. Based on long-term integrated monitoring in tourist caves in Bulgaria (Speleo-MIKS) and trends in climate change, the health hazards and probability of their increase against the background of intensifying global changes have been analyzed. Examples of the consequences of episodic natural cataclysms such as floods after extreme rainfall in some of the show caves and hazards of collapses during tectono-seismic activity are also given. The hazards from socio-economic global changes are also included: effects of land-use reorganization in cave system areas and of pandemics on show cave attendance. The influence of the tourist flow as a factor for changes in the cave environment is discussed.