2.1.3. Procedure
Upon arrival, the experimenter checked whether participantshad conformed to instructions on how to dress for the experiment(i.e. shoes, socks, long trousers, and a long-sleeve shirt). If not, par-ticipants were asked to either put on items of clothing provided, orto take off some clothing (this was necessary for two participants).Participants were then given information sheets about theexperiment, signed the consent form, and filled in the backgroundsurvey. The study was presented as testing the impact of dif-ferent environmental conditions on thermal comfort, with nospecific conditions mentioned. The whole preparatory period lastedabout 20 min and took place in a windowless basement room justoutside the climate chamber with lighting and temperatures con-stant across participants. In addition to information collection, thepreparatory period ensured that all participants were adapted to asimilar temperature and illumination before the experiment; andthat they had been sitting still for about 20 min in order to achievea similar level of pre-experiment metabolic rate.After this period the participants were led into the climatechamber two at a time. During the experiment participants had tosit on the chairs provided and read material that they had broughtthemselves. Reading material was supposed to be leisure readingmaterial, i.e. no course-work. Magazines were provided for thosewho did not bring any reading material. A conscious decision wastaken not to prescribe the reading: the same material could havevery different effects on different participants, which could in turnalso impact on comfort. For the purpose of the study it seemed neg-ligible that this decision might result in slight difference in photonsmeeting the eye: there are no grounds to expect any bias, i.e. par-ticipants under one light reading one type of material and thoseunder the other light a different type of material, since readingswere chosen beforehand. No participants reported suspecting thestudy related to lighting in the debriefing after the study.