When my wife gets overheated (working outside or jogging on a warm humid day), she is susceptable to migraines (including vomiting) almost 100% of the time. When sick, she treats the back of her neck just under the back of her skull with an ice pack. One of the things that seems to help if the headache doesn't go away is a neck adjustment (chiropracter or atlas). If this treatment works, she recovers within 24 hours. However, this treatment doesn't work all the time but seems to work most of the time. Also, I might want to note that we have been told that one of her blood vessels running up the back of her neck is larger than normal. It does not seem to warrant any additional attention based on what the doctors have said but apparently was above average in size enough to mention.