Abstract The development and implementation of mobile tracking systems to locate people buried under ruins after disasters or hiding inside containers and trucks during smuggling would help to protect lives and would greatly aid urban rescue teams and border control authorities. Requirements for such systems are that they should provide rapid analysis with low false positives and negatives to enable high control rates and long operational readiness. Current detection systems that employ thermal imaging or carbon dioxide measurement have several shortcomings and suffer from high false-positive rates. Portable analytical instruments that provide a chemical fingerprint of volatile compounds associated with the human body can potentially fulfill these requirements. This chapter discusses the challenges involved in the detection of entrapped or hidden human beings and presents techniques and endeavors focused on human volatile emissions to achieve this goal.