A hot flash is a feeling of warmth spreading over the body that is often most strongly felt in the head and neck regions. Hot flashes may be accompanied by perspiration or flushing and usually last from 30 seconds to several minutes.
I have listed the hours along each method. In store. If you are in a Walmart store the customer service desk is open between 8am-10pm. The service desk is generally at the front of the store near the optical department. By phone. You can call 1-800-WALMART between 7am-6pm.
According to the Baltimore Sun article (see Related Link), this year (2009) Wal-Mart will be open 24 hours-from Thanksgiving night through Black Friday-to help lessen the amount of people coming through. Updates: For 2010, the case might be different depending on what state and Walmart shop you are planning to buy.