How is temperature defined in the context of physical evidence?

In the context of physical evidence, temperature is specifically defined as the degree of sensible heat of a body as measured by a thermometer or similar instrument. This definition emphasizes the practical aspect of temperature measurement in forensic science and fire investigation.

Sensible heat refers to the heat that can be felt and measured with standard devices, and it provides critical information about the thermal characteristics of materials involved in an investigation. For example, knowing the temperature can help investigators understand the conditions present during a fire, which is vital in determining the fire's origin and the materials that may have been involved.

The other choices, while related to temperature concepts, do not accurately define what temperature is in this specific context. The measure of energy present in a substance relates more to thermodynamics and internal energy rather than temperature itself. The temperature at which a substance ignites refers to the concept of ignition temperature and is a distinct measure relevant to combustion but doesn't encompass the definition of temperature. The change in temperature over time describes a dynamic process rather than providing a static definition of temperature. Thus, option B captures the intended meaning and use of temperature in the study of physical evidence in fire investigations.