Routinely used in microbiology laboratories, baths create specific conditions to incubate samples that cannot be subjected to a naked flame. Either analog or digital controls set the constant temperature as well as the stirring or shaking additional operating mechanisms. Typically using water to gently apply heat to contained samples, oil and beads also used when elevated temperatures or more efficient methods are required. The baths may come with lids to stop heat from escaping and prevent outside contamination.