Normally ketones are not found in urine.
When ketones are found in urine,then most likely cause in general is diabetes.
But high ketones can be found in other conditions also like
abnormal state of nutrition like anorexia,starvation
taking more of proteins and less of carbohydrates,as in Atkins diet
You should consult a internal medicine specialist and get yourself examined and investigated properly.
Having cold can lead to high ketones in urine.
I hope it helps