Evaluation of indoor hospital acclimatization of body temperature before COVID-19 fever screening

This study was planned to verify whether body temperature stabilization may be needed when accessing healthcare facilities during periods of cool outdoor air temperatures. A total number of 65 patients with readable forehead temperature measures were included in this study (mean age, 62±18 years; 55% females). The external and indoor air temperatures ranged between 8.0-9.0 °C and 22.5-24.0 °C, while the mean time spent outside the building was 11±6 min. The mean forehead temperature recorded upon phlebotomy center admission (35.9±0.3 °C) was significantly lower than that measured 5 min afterwards (36.1±0.2 °C), displaying mean difference of 0.28 °C (95%CI, 0.23 to 0.33 °C; p<0.001), with maximum bias as high as 0.8 °C. Values remained unchanged after excluding patients wearing headgears (n=16; mean difference, 0.26 °C; 95%CI, 0.21 to 0.32 °C; p<0.001). Highly significant Spearman’s correlation was found between the two repeated individual forehead temperatures (r= 0.75; 95%CI, p<0.001), whilst delta forehead temperature ([5 min °C] – [entrance °C]) was not associated with sex (r= -0.21; p=0.092), age (r= -0.06; p=0.612), headgears use (r= 0.09; p=0.495) or reported time of outdoor stay (r= -0.08; p=0.541). We hence conclude that ∼5 min indoor acclimatization period is necessary before systematic screening of forehead temperature.