In the near future, electronic cabinets of data centers will house high performance chips with heat fluxes approaching and associated high volumetric heat generation rates. With the power trends in the electronic cabinets indicating 60 kW cabinets in the near future, the current cooling systems of data centers will be insufficient and new solutions will need to be explored. Accordingly, the key issue that merits investigation is identifying and satisfying the needed specifications of the new thermal solutions, considering the design environment of the next generation data centers. Anchoring our work in the open engineering system paradigm, we identify the requirements of the future thermal solutions and explore various design specifications of an ideally open thermal solution for a next generation data center. To approach an open cooling system for the future data centers, the concept of a thermal solution centered on the multiscale (multilevel) nature of the data centers is discussed. The potential of this solution to be open, along with its theoretical advantages compared with the typical air-cooling solutions, is demonstrated through some scenarios. The realization problems and the future research needs are highlighted to achieve a practical open multiscale thermal solution in data centers. Such solution is believed to be both effective and efficient for the next generation data centers.