Below are thermoregulator indicators and parameters researchers are using in animal studies.
Core Body Temperature
This can be measured via telemetry by implanting a temperature telemetry device in the intraperitoneal space. Rectal probes have been used for this measurement in the past and are best used in acute monitoring of anesthetized animals. Core temperature may be averaged over time in most cases, but before averaging, ensure you understand the particular animal's circadian rhythm whether it be daily, weekly, or monthly so you can accurately subtract the normal rhythm to detect a true fever.
Infrared cameras can capture skin temperature gradients in some cases. Fur from the animal may impede the measurement. Peripheral temperature measurements can also be taken by placing a temperature telemetry device subcutaneously or via a hardwired thermistor probe in anesthetized models.
In some animal models, specific localized temperatures may be recorded such as Brown Adipose Tissue (BAT), brain, tail, or other specific tissue and organ temperatures. A thermistor at the end of a temperature probe may be required to enable this measurement. DSI offers telemetry products which have external thermistor probes for use in small animals. These are commonly used in neonatal, target organ and metabolic studies looking at quick temperature changes.