# Utility of non‐contact thermometers in neonatal intensive care: Effects of incubator conditions and measurement sites

## TL;DR

Non-contact thermometers can reliably monitor neonatal body temperature, especially when used on the trunk and averaged across multiple sites.

## Contribution

The study identifies optimal measurement sites and strategies for non-contact thermometers in neonatal incubators.

## Key findings

- NCITs at the non-contact trunk surface showed best correlation with axillary CT in high-temperature incubator conditions.
- Averaging NCIT readings from multiple sites improved correlation with axillary CT measurements.
- Limits of agreement for NCITs were wider in low-temperature incubator conditions.

## Abstract

Non‐contact infrared thermometers (NCITs) are non‐invasive alternatives to conventional contact thermometers (CTs). However, the accuracy of NCITs may be affected by measurement environments and body surface sites. This study evaluated the reliability of NCIT measurements under various temperature conditions in neonatal incubators and explored optimal measurement strategies.

Preterm neonates with a corrected gestational age of 25–32 weeks were enrolled in this observational study. Body temperature was measured using NCITs at the axilla, forehead, and both contact and non‐contact surfaces of the trunk, and by CT in the axilla. Measurement environments were classified into two groups: high temperature (HT [≥33°C, ≥60% humidity]) and low temperature (LT [28.5–32.9°C, ≥40% humidity]).

Body temperatures measured by NCIT correlated with axillary temperature measured by CT (axillary CT) but varied by site. The non‐contact trunk surface measured by NCIT had the best correlation with temperature measured by axillary CT and had the smallest limits of agreement in the HT group. However, Bland–Altman analysis showed wide limits of agreement for single‐site NCITs in the LT group, although the correlation at the contact trunk surface improved with corrected gestational age. Averaging NCIT readings from the axilla and both trunk surfaces yielded stronger correlations with axillary CT (p < 0.05).

NCITs appear to be a practical option for neonatal temperature monitoring, particularly when used at trunk surface sites. Taking average measurements from multiple sites may enhance accuracy and aid in creating better measurement protocols in NICUs.