Winter Hiking Boots

I have a pair of boots brand Hi-Tec hiking winter are very comfortable, and expensive too. http://www.hi-tec.com/us/46238-product-blackcomb_400_quik_zip-all.html
I moved to the desert (Las Vegas) and found that it gets quite hot during the summer. Can I use my winter boots or should I buy desert boots? In other words, my feet too hot in the summer of all the insulation and so on?

I use my standard winter boots in the summer and have not experienced problems. I am in England, so I can not claim to have put a thorough test!
I was wearing my old boots in India when I was there and I found that, while I was wearing cotton socks breathe I do not need a desert boot.
You can check on your plant, well, I have a pair that harden as the temperature drops, which means the opposite is also true. The last thing you want is to have your steps melt!

It depends entirely on you and your boots.
My feet tend to sweat a bit, so I prefer to wear boots that breathe well, especially in summer. So I normally do not wear my winter boots in summer. But I do have an old pair of leather boots that I wore full all summer long (80deg +) for winter (below 0). But I would not do that with any other of my boots.