With freezing temps and more snow bearing down on the Front Range this week, Denver officials said they plan to adjust the policy dictating how cold it must be before the city opens recreation centers to people as emergency warming shelters. The impending changes were discussed Wednesday morning during a meeting of the Denver City Council’s safety committee in which some committee members criticized the current policy for not being informed by any medical research. Members of the city’s housing, public health and public safety departments appeared before the committee for a briefing on winter shelter policies.