Unite, which represents thousands of employees in the hospitality sector, said it is concerned staff do not have training or the correct personal protective equipment (PPE) to be tackling the Covid-19 pandemic on the frontline.
"Hotel workers, many of whom who are on the minimum wage, are being required to undertake new roles in a highly stressful environment without any proper safety guidelines," said Dave Turnbull, Unite’s national officer for hospitality.
“While some hotels are taking a responsible attitude and are trying to introduce guidance to protect staff, that is not true of them all.
"The hotel chains who have answered the call to provide emergency accommodation must understand that they are risking lives if the correct safety measures are not put in place."
He said Unite is working with the department for business, energy and industrial strategy (BEIS) on the issue, "demanding" the government intervene "immediately".
This comes as hotels around the country offer their accommodation to the help the NHS.