A flexible-to-rigid tube is flexible when routed and is then rigidized to increase burst strength. According to the preferred embodiments of the present invention, the flexible-to-rigid tube is included in a cooling plate assembly for transferring heat from electronic components mounted on a circuit board. In one embodiment, the flexible-to-rigid tube (while in a flexible state) includes a polydimethylsiloxane (PDMS) or other silicone containing pendant or terminal epoxy, vinyl and/or acrylate functional groups and an initiator (e.g., a sulfonium salt photoinitiator, a free radical photoinitiator, or a thermal initiator). In another embodiment, triallyl isocyanurate (TAIC) and an initiator are incorporated into a conventional PVC-based tubing material. The flexible-to-rigid tube changes from the flexible state to a rigid state via formation of a cross-linked network upon exposure to actinic radiation or heat.