With Christmas Day just two weeks away, WISN 12 News reporter Kent Wainscott examines whether the bitter cold may be taking a bite out of holiday retail sales.Shoppers packed the stores over the Thanksgiving weekend, but now this bitter cold blast may be keeping some shoppers home."I'd say so, yes. Yeah, a lot of people don't like the cold," Wauwatosa holiday shopper Dan Geary said.VIDEO: Cold weather may affect way people shop"If you do it online, you sit at home with your jammies with your cup of coffee. It's great," West Bend holiday shopper Vikki Brendelson said.The National Retail Federation predicts up to a 15 percent jump in online buying this year, but said it has no way to measure the impact of the weather but doesn't think it's enough to impact holiday season.Not everyone agrees."Will it have an impact overall on this holiday shopping season?" Wainscott asked a shopper."I think it will. I think some people are not going to come out. I think it's definitely going to be slower," Milwaukee holiday shopper Joy Leibold said.But while the cold and snow may put fewer shoppers out on the road this holiday season, it's likely to put more packages on the road.At the UPS distribution center in Elm Grove, there has been an uptick in business in the past week."I know it's cold out there, but it's easy for you to go online and order your packages," said Andy DeLeon with UPS.Still, holiday bargain hunters like Leibold think the cold will only impact other shoppers."It is 10 degrees today, and the temperature is dropping. At what point does it get too cold to get out to the stores?" Wainscott asked."I don't think it ever gets too cold to shop -- ever," Leibold said.UPS said its busiest day for deliveries will be Tuesday.