In caves, know the quality of the air or in spaces without ventilation such as post-siphon bubbles, mine galleries, etc. and other places where non-breathable gases or low concentrations of O2 can be stored, it is a fundamental and mandatory question to guarantee the safety of explorers. At present, the study of gases in cavities is allowing to know and obtain data on the dynamics of gases and air, from the deepest areas and their relationship with morphologies, corrosive processes, and their effects on the underground system, providing new methods to understand the processes involved in the formation and development of cavities. A selection of equipment that has been used and tested in cavities is compiled. The equipment is grouped into two sections, the first "essential equipment", which includes measuring instruments that all groups of cavers should carry as they are the ones that can guarantee the breathing of air in closed environments or warn us of the risks due to the accumulation of gases. A second group, which we call "equipment for climate analysis", which allows obtaining data on the dynamics or the state of the climate of the cavities.
Keywords: Citation, Climate equipment, caves, CO2, temperature, humidity, gases