what type of test is normally done to see if you have throat cancer?

Biopsy or taking a sample of tissue is the only to confirm the diagnosis of cancer.  Of course, one could make the diagnosis based upon confirmatory symptoms, eg unexplained weight loss, blood in stools, plus ribbon flat or pencil thin stool all add up to colon cancer until proven otherwise.  Or unexplained weight loss in heavy smoker with change in voice and difficulty swallowing, perhaps accompanied by swollen, hard, matted lymph nodes in neck. 

I'm sorry to hear about your uncle's misfortunes.  Still without knowing what test was performed, it's difficult to hazard a guess as to what led to the complication requiring that he be brought back.  Perhaps he aspirated something that led to pneumonia?  Perhaps something was cut that shouldn't have been?  Bleeding (although I don't think this would lead to severe chills)? 

Best to identify one person in the family to find out from your uncle's physician(s) what happend and then broadcast back to the family, rather than have each of you ask the same questions repeatedly.  Good luck to you all.