Temperature readingBACK

I am asked, very frequently, by parents that the head always feels warm while the hand and feet (peripheries) are cold, especially when a child has fever. In this blog I shall try to explain and reason out why this is so.

Our head and chest contain our vital organs which need to be maintained at a particular temperature for optimal functioning. Being vital organs they have constant blood supply. On the other hand the peripheries can remain starved of blood for short periods without any harmful effect. Hence, the body's regulatory mechanism ensures that the vital organs get priority of both oxygen and temperature over the peripheral areas.

One must have noticed the use of tongs while cooking. The end near the fire is always warmer then the end being held by hand. This example exemplifies the description provided above for the body.

With this background one should understand the importance of recording the temperature at one site. Temperature can be recorded at the following sites:

• rectum
• mouth (oral)
• axilla
• groin
• forehead
• tympanic (ear)

The ideal temperature is the rectal one. However it is not easy to record though this is the most common site used in infants. The next best is the mouth temperature. However the most commonly used site is the axilla (side) or groin. The temperature recorded at the forehead or the ear is not a very reliable one.

My advice to my patients/parents is to record the temperature at one site only and leave it for the doctor to interpret it. The axillary temperature will be lower than the oral one and the variation shall depend on the room temperature. In cold conditions the variation can be as much as 0.5-1 degree Fahrenheit whereas there will be hardly any variation in warm conditions.