They have to really have a good little internal heater going and a high metabolism so that they can generate enough heat to stay warm in the winter. Then in turn because they’re generating so much heat that’s not something you can necessarily shut off in the summer. So most of the time alpine stays pretty cool in the summer but if you get a really really hot streak in the alpine, pikas are not able to thermoregulate or cool themselves down very easily because their metabolism is so high.