Positive chills yesterday.
 patient has a fever
(ROOT (NP (NP (NP (JJ Positive) (NNS chills)) (NP (NN yesterday))) (. .)))
(ROOT (S (NP (NN patient)) (VP (VBZ has) (NP (DT a) (NN fever)))))
( ( ( Positive chills ) yesterday ) . )
( patient ( has ( a fever ) ) )