Rectal and gastrointestinal temperature differ during passive heating and subsequent recovery

We aimed to compare rectal temperature (T-rec) and gastro-intestinal temperature (T-GI) during passive heating and subsequent recovery with and without ice slurry ingestion. Twelve males (age: 25 +/- 4 years, body mass index: 25.7 +/- 2.5 kg m(-2)) were immersed in hot water on two occasions (T-rec elevation: 1.82 +/- 0.08 degrees C). In the subsequent 60-min recovery in ambient conditions, participants ingested either 6.8 g kg(-1) of ice slurry (-0.6 degrees C, ICE) or control drink (37 degrees C, CON). During passive heating, T-rec was lower than T-GI (P < 0.001), in the recovery, T-rec was higher than T-GI (P < 0.001). During passive heating, mean bias and 95%LoA (Limits of Agreement) were -0.10(+/- 0.25)degrees C and -0.12(+/- 0.36)degrees C for CON and ICE, respectively. In the recovery, mean bias and 95%LoA were 0.30(+/- 0.60)degrees C and 0.42(+/- 0.63)degrees C for CON and ICE, respectively. T-rec and T-GI differed during both heating and recovery, and less favourable agreement between T-rec and T-GI was found in the recovery from passive heating with or without ice slurry ingestion.