How did Timothy protect Phillip from the storm?

In Chapter 15, a large storm washes over the island. The wind blows over the hut in which Phillip and Timothy live, and Timothy protects Phillip by covering Phillip's body with his own. They spend two hours that way, as the storm blows over them with lashing rains and strong winds. The storm is so harsh that they can barely breathe.
As the sea begins to come up the beach, Timothy brings Phillip to the palm trees on the rise for shelter. Timothy ties Phillip and himself to the tree. Water laps against their ankles and feet, and Timothy continues to protect Phillip with his body against the driving wind. They remain that way for about an hour, until the wind dies down and they can untie themselves from the tree. When the eye of the storm passes over and the winds pick up again, worse than ever, Timothy again ties Phillip to the tree and protects the boy with his body. Several large waves pass over them, and, in the end, the storm kills Timothy while Phillip survives. Timothy gives his life to protect Phillip.