I was shopping in a few retail stores this past weekend, and noticed that in most cases, they had the temperature cranked up high.
I realize that your staff need to feel comfortable while they're working but it's important to realize that your revenue comes from your customers. And, if they are uncomfortable in your store, which I was by the way, they will leave and give their money to one of your competitors.
I'm not suggesting that you drop the temperature by 10 degrees but it is critical to recognize that most customers (at least in the northern hemisphere) wear coats because it is cold outside. That extra layer of heavy clothing adds heat to their body and if the temperature in the store is set at high, it becomes unbearable for most people.
Seperate yourself from you competition by making it comfortable for your customer to shop in your store.