When are rats hot? - briefly
Rats show increased body temperature during fever, when ambient conditions rise above their thermoneutral zone, or under stress‑induced hyperthermia. They also become warm during intense physical activity.
When are rats hot? - in detail
Rats maintain a core temperature of approximately 36–38 °C (97–100 °F) through internal mechanisms. Their body heat rises above this baseline when specific physiological or environmental factors intervene.
Elevated temperature occurs during:
- Fever: Infection or inflammation triggers the release of pyrogenic cytokines, resetting the hypothalamic set‑point and causing a controlled rise of 1–3 °C.
- Heat exposure: Ambient temperatures above 30 °C (86 °F) overwhelm evaporative cooling, leading to passive hyperthermia if ventilation is insufficient.
- Intense activity: Prolonged running, climbing, or forced exercise increases metabolic heat production, temporarily pushing core temperature several degrees higher.
- Stress response: Acute stressors such as predator cues or handling stimulate sympathetic output, raising heart rate and metabolic rate, which can modestly increase body heat.
- Reproductive cycle: Female rats in estrus exhibit a slight temperature elevation due to hormonal fluctuations.
- Pharmacological agents: Certain stimulants (e.g., amphetamines) and thermogenic compounds boost metabolism, resulting in measurable temperature spikes.
Measurement of these changes relies on rectal probes, implanted telemetry devices, or infrared thermography. Normal diurnal variation is limited to about 0.5 °C; deviations beyond 1 °C warrant monitoring for pathology. Preventive strategies include maintaining cage temperature between 20–26 °C (68–79 °F), providing adequate ventilation, and minimizing stressors.