Which type of mortis indicates the body's temperature becoming equal to the surrounding temperature?

The process that indicates the body's temperature becoming equal to the surrounding temperature is known as algor mortis. This phenomenon occurs after death and is a vital aspect in the study of post-mortem changes. As the metabolic processes cease, the body begins to cool down, losing heat to the environment until it reaches equilibrium with the ambient temperature.

This cooling process can provide forensic investigators with important information regarding the time of death, as the rate of temperature loss can vary based on factors such as the environment, clothing, and body type.

The other options refer to different post-mortem changes: rigor mortis is the stiffening of the muscles after death, livor mortis is the pooling of blood in the lower parts of the body due to gravity, and cadaveric lividity refers to the discoloration resulting from this pooled blood. Each of these processes also plays a role in forensic science but does not pertain to the body's temperature adjustment to its surroundings.