Fig. 1.

Water temperature stability in thermos flasks. Water temperature was measured with a calibrated thermometer at the start of the incubation and after 2 and 4 h of storage. Each thermos flask was opened only once during the 4-h storage to measure the temperature, and sealed again immediately after. Each condition (starting water temperature [35.5 °C, 37 °C or 38 °C] and storage temperature [RT, 32 °C or 42 °C] combination) was evaluated 3–4 times. Graphs show the mean and SD for each condition over time