Bathing in Hot Water Between the Death and Burial of One's Grandfather

Is it permissible to shower between the death and burial of one's grandfather?

It is permitted to bathe in hot water and there are no mourning laws applicable, since mourning laws for close relatives are only practiced from the time of burial. Even though laws of mourning begin for his father, they do not apply to him.

The early scholars were divided on whether mourning laws are practiced before the burial by the mourner himself. In practice, the Shulchan Aruch ruled in chapter 341, paragraph 5, that all mourning laws are practiced from the time of death. However, Trumas HaDeshen wrote when a relative of a relative dies, these laws are only practiced from the time of burial. The legal decisors explained that since there is a disagreement among the scholars regarding the mourner himself, even though the Shulchan Aruch ruled stringently, they ruled leniently regarding mourner’s close relatives.