A good set of winter tires, (as you have), have what is called an ice compound in the rubber. This allows the tread of the tire to stay pliable at very cold temperatures and follow the contours of the road, providing maximum traction, as opposed to the tread freezing, not following the contours of the road and traction going out the window. This is why a good set of winter tires is always a better choice for snow traction than merely an all season tire, which is a jack of all trades and a master of none. So using this type of tire in hot weather, will have the tire wearing quicker than what was intended by the manufacturer.
A winter tire used in summer/hot temperatures will wear comparatively quickly, as it's not designed for this use. The tread blocks in the tire are much chunkier than with an all season tire, so the winter tire also doesn't disperse heat very well, gets hot and as the rubber in the tire gets hotter it also gets softer, again causing comparatively rapid wear. In severe cases, the tire can get so hot that it fails/blows out. Also, winter tires don't handle as well, or brake as well as an all season tire on roads where the environment is warm/hot.
So there's several things to consider. I hope this helps you out.