A chill or shivering sensation often associated with fever or the onset of illness (used commonly as 'to have chills').
昨夜から悪寒がして、熱っぽい。
I've had chills since last night and feel feverish.
悪寒がして震えが止まらないので、すぐに布団に入った。
I couldn't stop shivering from the chills, so I got into bed immediately.
検査の結果、悪寒は初期のインフルエンザの症状だった。
The tests showed that the chills were an early symptom of the flu.