... a dehydration prevention system according to this Economist article, http://www.economist.com/search/displaystory.cfm?story_id=9719013&CFID=27442206& CFTOKEN=67076189 Borrowing from nature, about biomimetic architecture.
It says a similar trick to beetles' use of condensation to collect drinking water is used by camels to prevent them losing moisture as they exhale. 'Moisture secreted through the nostrils evaporates as the camel breathes in, cooling the nostrils in the process'. Moisture secreted through the nostrils? That must be what you are covered in if a camel snorts all over you. Ie, mucus.It continues, 'When the camel breathes out, moisture within the air then condenses on the nostrils.'
So, it seems in the breathing cycle, there is a change in the contents of the camel's nose, from mucus before breathing in to moisture after breathing out. Does the camel then swallow the moisture? How is it returned to the body. At the same time as this cycle, there is a cooling and warming cycle.
Inside the nostril it must be like a soft air conditioner with lots of protuberant flanges to increase exposure to the air.
This is an interesting contrast to dogs which breathe through the mouth to cool off. The cooling from evaporation of saliva through latent heat of fusion (?) they use to regulate body temperature.
The camel however is using the cooling to collect moisture from its own lungs, not to stay cool.