http://www.biologynews.net/archives/2011/09/12/scientists_utilise_breath_and_sweat_to_detect_trapped_humans.html
This article describes a study involving a simulation of a collapsed building. Volunteers were placed in this simulation to test sensors in the hopes of developing portable devices to detect humans trapped in the remains of disasters such as that of 9/11 and, more recently, Japan and New Zealand. These sensors detected molecules in the air traveling through the building, as well as organic compounds, which were released through the breath, sweat, and other bodily fluids of the individuals in the simulation.
