Core temperature monitoring is important in order to assess the efficacy of the rewarming measures.
This should be accomplished by the use of a rectal or oesophageal thermometer.
Note that the rectal temperature may lag behind the core temperature increases due to impaction into frozen faeces.
Note that the oesophageal temperature reading may be falsely elevated when concurrent heated, humidified oxygen is being administered.
It also requires the patient to be intubated.