Disclosed herein is a cushioning device that includes a plurality of fluid cells each containing fluid for supporting a load. The cushioning device further includes a manifold system interconnecting the plurality of fluid cells, a first reservoir, and a second reservoir connected to the first reservoir in series. The first and second reservoirs are connected with a pressure relief valve allowing fluid to escape from the first reservoir to the second reservoir when the pressure in the first reservoir exceeds a threshold and a check valve allowing fluid to flow back from the second reservoir to the first reservoir. Further disclosed is a method of cushioning a body with a cushioning device.
