SOS!! DOG SHAKING/SHIVERING UNCONTROLABLY!!!?

just now my mom called me over to the bathroom and was holding dolly(our 5 year old golden retriever) and she(dolly) was shaking uncontrollably. we both held her and coaxed her then she calmed down so i left, but then she started up again and im really worried!! its really late and no vet is open so were stranded plz help!!!