Related Experiment Video
Updated: Aug 7, 2026

Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction
Published on: April 24, 2016
Depression of sublingual temperature by cold saliva
Abstract:
Sublingual and oesophageal temperatures were compared at various air temperatures in 16 subjects. In warm air (25-44 degrees C) sublingual temperatures stabilized within plus or minus 0-45 degrees C of oesophageal temperatures, but in air at room temperature (18-24 degrees C) they were sometimes as much as 1-1 degrees C below and in cold air (5-10 degrees C) as much as 4-4 degrees C below oesophageal readings. The sublingual-oesophageal temperature difference in cold air was greatly reduced by keeping the face warm, but it was not reduced in two patients breathing through tracheostomies and thereby eliminating cold air flow from the nose and pharynx. Parotid saliva temperature was low and saliva flow high during exposure, and cold saliva seemed to be mainly responsible for the erratic depression of sublingual temperature in the cold. These results indicate hazards in the casual use of sublingual temperatures, and indicate that external heat may have to be supplied to enable them to give reliable clinical assessments of body temperature.
Related Concept Videos
Thermosensation
Freezing Point Depression and Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
Decreased Body Temperature
Assessing Body Temperature - Oral
Step 1:
Start by practicing proper hand hygiene to prevent the spread of microorganisms.
Step 2:
Take the thermometer out of the charging unit, switch it on, and wait for the ready sign.
Step 3:
Gently slide the probe cover until a click is heard. This simple action prevents cross-contamination and ensures the correct placement of the probe cover.
Step 4:
Instruct the patient to open their mouth and place...
Sublimation
Freezing Point Depression and Boiling Point Elevation

