I am on nexito 15mg and occasionally takes etizest 0.25mg. Today very weird things happened, I live in North India where currently it has chilling winters. Due to some neck stiffness I put cold pack 15 min each on both neck sides and back of neck. Was lying in just shorts and suddenly after removing ice pack I felt shivering and it was so intense that I thought of being admitted to hospital at night only. The shivering was not stopping and I took etizest 0.25mg and after 20mins walking in a room of heater it settled down. What was that, I was very much normal before the ice pack.