Well dogs can't really sweat through there skin so I would recomened for you to go to the vet A.S.A.P .
Dogs do not sweat through their skin; Only their noses. It sounds to me like she is leaking urine during her sleep. This is rather common and there are medications to control it. However, because she is so HOT, I would think she is running a fever. This could also explain the urine leaking...She possibly has a urinary (UTI) infection or something of the sort. Also, very treatable with antibiotics. I would take her to the vet for a urinalysis with culture. That way they can prescribe the correct antibiotic for the bacteria and there is no guessing.... The most important thing in your message is that you not only adopted, but adopted a SENIOR! (That makes her (And you) even more special!) Enjoy, enjoy, enjoy! She will reward you tenfold...........Thank you for saving her............You have been blessed...........Karla