A&D Thermometers UT-103 Digital

The traditional figure of 37°C as the average normal body temperature is a useful reference point, but individual normal temperature varies. Most healthy adults fall within a range of approximately 36.1°C to 37.2°C for an oral measurement. Temperature also fluctuates naturally throughout the day — it tends to be slightly lower in the morning and higher in the late afternoon. A reading of 38°C or above is generally considered a fever. If you are unsure what is normal for you personally, taking a few baseline readings when you are well gives you a useful individual reference point.

For adults, a temperature above 39°C that does not respond to appropriate fever management at home, or any fever accompanied by a severe headache, stiff neck, sensitivity to light, difficulty breathing, chest pain, or a rash that does not fade under a glass, requires same-day or emergency medical attention. For babies under three months, any fever is a medical emergency warranting immediate advice from 111 or a GP. For young children aged three months to five years, a temperature above 39°C requires prompt medical assessment, particularly if the child seems unusually unwell.

Not exactly. Underarm (axillary) temperatures typically read approximately 0.5°C lower than oral measurements, as the armpit does not achieve the same temperature as the core of the body. This difference is widely recognised and accounted for in clinical guidance. If you are recording underarm temperatures for a GP, it is worth noting the measurement site alongside the reading. For most home monitoring purposes, the important thing is consistency — always measuring at the same site allows you to track changes meaningfully over time.

For younger children who resist having a thermometer placed in their mouth, the underarm (axillary) route is generally easier to manage and is widely used for young children in the UK. Place the tip of the thermometer firmly in the centre of the underarm and hold the child's arm gently but securely against their body for the duration of the measurement. A beep will signal when the reading is complete. For very young babies, a rectal measurement is clinically the most accurate, but this should only be done on medical advice with an appropriate thermometer technique.

First, check the battery level — a depleted battery is a common cause of unexpected readings on digital thermometers. Ensure the thermometer has been at room temperature for a few minutes before use if it has been stored somewhere cold. For oral readings, confirm the tip was positioned correctly under the tongue and that the mouth was closed throughout the measurement. For underarm readings, ensure the tip was in direct skin contact and not touching clothing. If readings remain inconsistent or implausible after these checks, the device may need to be replaced.

The UT-103 can be used for axillary (underarm) measurements in babies and young children, which is the most commonly used site for infant temperature-taking in a home setting. For very young babies, any raised temperature should be acted on quickly — always consult your GP or call 111 for any fever in a baby under three months old, regardless of how high the temperature reads. Do not rely on thermometry alone to assess the wellbeing of a young infant.

Wipe the thermometer tip with a clean tissue or a mild antiseptic wipe after each use and allow it to dry fully before storing. Do not submerge the device in water or cleaning solution. If the thermometer has been used for rectal measurement, it should be reserved exclusively for that site going forward and not used for oral or underarm measurement on any patient. Clearly label or store separately any thermometer designated for rectal use to avoid confusion.

Yes. Pearl Chemist Group stocks a range of thermometer accessories, protective cases, and battery types in store and online. If you are unsure which battery your UT-103 uses, check the instruction manual or bring the device in to any Pearl Chemist Group branch and our team will help you find the right replacement. Browse our full range of home health monitoring products for everything you need to keep your home health kit well equipped.