Subject: How does heat gain in animals by convection work (or is it possible)?

Recently, in my class on physiological ecology, we were talking about convection and conduction, and how they affect gains/losses of heat by an animal.  One thing was noted by the professor in passing, which didn't make intuitive sense to me.  Can you confirm or refute (and explain) the statement that animals can gain heat by convection?  I can understand the loss of heat by convection, but not the gain of heat.  The American Heritage Dictionary defines convection (in physics) as 'Heat transfer by fluid motion between regions of unequal density that result from nonuniform heating'.  How does a solid surface (i.e., an animal's skin) have a fluid motion?  What am I missing?  Please be as detailed as you can in your answer.  Thanks!

Re: How does heat gain in animals by convection work (or is it possible)?