I remember when I bought a fire stone for my Growlithe I kept it in my backpack for the longest time... He ended up finding it and when I wouldn't give it to him he kept whining at me until I finally did.

_{[And that's how he ended up with an oversized bear-dog.]}

As for traveling in the winter, I've never had a problem with it. I actually like it more than traveling in the summer, but I've got some fire types to keep my warm on the trail.