By Vassia Barba The cruel conditions that a US citizen has been subjected to while in detention in a Russian prison have emerged, including a lack of hot water, limited access to hygiene facilities and freezing temperatures. Ksenia Khavana, also known as Ksenia Karelina, has been detained by Russia’s Federal Security Service (FSB) on charges of treason after she reportedly made a donation of $51 to a charity supporting Ukraine. Karelina, 33, holds both US and Russian citizenship due to her marriage to an American and had returned to Russia to visit her family. Her arrest took place in the city…