Panels are extended from housings affixed to equipment racks that abut a cold aisle, during normal operation of the electronic equipment installed in the racks, in order to fully or partially contain the cold aisle (e.g., within a data center). The panels may extend automatically (e.g., during powering up of the equipment) and/or in response to a specific control. In response to an emergent condition (e.g., fire), and/or activation or deactivation of a control, the panels automatically retract. The retraction allows a fire suppression agent (e.g., water, foam) to enter the aisle, may allow easier access to the equipment, and/or provide other benefits. The panels are generally transparent in order to allow light to enter the aisle even when the panels are extended. In its extended orientation, a given panel may engage or be in contact with an opposing panel (e.g., across the cold aisle) and/or an adjacent panel.