Sleep Cool Study As they developed mattress prototypes, Sleep lCool's product team measured their cooling and sleeping properties. According to one member of the product team, Sleep Cool recruited "an army of sleep testers" to gather performance data for their mattress prototypes147 of whom tested the final design. Specifically, the product team used sensors to measure the temperature of the mattress after a 7-hour period, simulating the time immediately before waking (i.e., at the end of the sleep cycle). They also used sleep monitoring equipment to record the number of minutes of "deep" sleep and the number of minutes awake during the 7-hour periodmore minutes of "deep" sleep is better: more time awake is worse. After sleeping on the mattress, subjects in the study were asked questions about their perceptions of comfort and other important attributes of the mattress. For comparison, sleep subjects went through the same testing process for the leading "bed-in-a box\" brand. Casper. and for the leading memory foam mattress brand, Tempur-pedic. Results of the Sleep Cool study are in the Excel file sleep_cooLstudy.xlsx