White's need 85F during day and can handle a 10F drop at night. It was "wanting to sit in your hand" because it's cold and it's looking for warmth. I've got no information that says for how long it can go without damage. Do know that frogs kept at temps below it's parameters over long periods can suffer permanent damage to their Kidneys and Lymph Hearts. Do you have family or friends nearby that could babysit frog until issue is fixed?