What Causes Shivering And Vomiting After The Vaginal Hysterectomy Surgery?

I had a vaginal hysterectomy 6 days ago, yesterday I was vomiting and went to lie down afer abou anhour sleep I woke up shivering from head to toe, my whole body was shaking for approx 1 hour even though I was wearing warm pjs and under my duvet, eventually I fell back to sleep and woke later and was ok, then later las night I suddenly broke into a cold sweat all over even though I felt hot, my hair m face my body everywhere was wet and clammy this only lasted about 10 mins then again I was ok, today I just feel nauseus, is this normal in my recovery process. I am 52 60kg and 5'6"