Abstract: Systems and methods are described for detecting heat stroke and monitoring cooling treatment of heat stroke. The system includes a rectal temperature probe including a flexible length and an indicator positioned on the flexible length to indicate when the probe has been inserted to a target insertion depth. A controller is configured to receive a signal from the probe indicative of a sensed temperature and to determine whether heat stroke is likely based on the sensed temperature. When monitoring cooling treatment, a cooling rate is calculated based on periodically sensed temperatures and, based on the calculated cooling rate, the system indicates whether the heat stroke is being adequately treated or if the current treatment methods are insufficient.