I m a candidate with cluster cycles every 18 to 24 months, the haunting experience been going on with me for at least 25 years now. I was on imetrix for a while until I had a heart surgery, now being told by my Doctor I can t use so much of it due to the risk factor concerning my heart. I m finding out now when an attacks come, I use a plastic bottle of cold water press against the temple of my head where the pain is intense, I come to find out that it eases the pain and relieves the headache , my question, is it safe?