Heart rate (green) and temperature (blue) changes during 10 minute exposure periods in phase II. The time instances at which exposure was switched on or off are marked by vertical lines and the curves are aligned according to the onset of the exposure. The length of the exposure periods varied slightly from recording to recording. Temperature values were written down manually at every minute during (and for several minutes after) the exposure periods. While start- and endpoints of exposure periods are aligned accurately with the heart rate curve, there may be slight (up to half a minute) misalignment between heart rate and temperature.