Re-oxygenation of post-mortem lividity by passive diffusion through the skin at low temperature.

Post-mortem hypostasis develops due to passive settling of the blood under the effect of gravity after death. Due to consumption of oxygen in the tissues by residual cellular activity after the circulation has stopped, lividity is composed of deoxygenated blood. It has been previously shown that cooling of a body causes lividity to oxygenate, changing from a dark red/blue to a pink/red color, due to hemoglobin's increased affinity for oxygen at low temperature. This study has confirmed that this occurs by passive diffusion through the skin, but that this can only occur within a limited time frame. The reasons for this process and its potential forensic application require further investigation.