Photo of one of the polar bears participating in our investigation into thermoregulation in polar bears. The study involved 25 bears at 11 different zoos across North America. Fecal samples were collected daily from each bear for at least a year to non-invasively monitor the hormonal response to increased ambient temperatures. In addition, 'thermal snapshots' were taken of several of the bears in summer and winter where we took thermal images and recorded behaviour after feeding them an ibutton which measured their core body temperature every minute (until they pooped it out).