When using an ice bath for physical cooling, the rectal temperature must not fall below

Under normal circumstances, when using an ice bath for physical cooling, rectal temperature should not fall below 30°C. The ice bath is primarily used for head cooling. If rectal temperature drops below 30°C during this procedure, it may lead to atrial or ventricular fibrillation and atrioventricular conduction block. Detailed explanations are as follows:

The purpose of ice bath cooling is to lower head temperature, mainly focusing on cerebral cooling while secondarily managing body surface temperature. This method helps prevent cerebral edema, reduces the metabolic rate of brain cells, decreases their oxygen consumption, and enhances the brain cells' tolerance to hypoxia, thereby minimizing brain cell damage. During ice bath cooling, care must be taken to avoid frostbite to the earlobes and occipital region. Therefore, rectal temperature should be maintained no lower than 30°C to prevent the occurrence of atrial fibrillation.

The method of ice bath cooling involves placing the patient's head in an ice cap. The back of the neck and both earlobes should be padded with sponge material. The drainage tube should be placed into a bucket to collect meltwater. Non-greasy cotton balls should be inserted into both ears to prevent ice water from entering. The eyes should be covered with Vaseline-impregnated gauze to protect the corneas. Check regularly whether the ice bath is damaged or leaking. When the ice in the bath melts, replace or add more ice promptly. Monitor the patient's temperature, maintaining rectal temperature around 33°C and never below 30°C, to prevent complications such as ventricular fibrillation.

If high fever persists, it is recommended to seek medical attention promptly to avoid delaying treatment.