Temperature is a vital sign which can be measured using various types of clinical thermometers. Pulmonary artery temperature is considered the ‘gold standard’, but this measurement is not usually clinically practical. There is currently no consensus for optimal alternative site or equipment. This research compares 178simultaneous measurements from 5 clinical areas, using two types of thermometers: tympanic and no-touch temporal. No-touch thermometers were all set to oral equivalent. Tympanic thermometers were adjusted to either oral (n=105) or core (n=73) equivalent. Maximum acceptable difference was identified as 1oC. Two data sets (oral/core; oral/oral) were analysed using Bland-Altman method on Excel programmes, comparing all thermometers and separating oral and core-equivalent tympanics. The two thermometers were found not to be equivalent. As a simple comparison between two thermometers, this research cannot identify which thermometer is more accurate.