What Causes Chilling Feeling In Abdomen During Masturbation Before Ejaculation?

Hey everyone, So for the past 3 or 4 times Ive masturbated, Ive noticed that there s a rather noticeable chill that i feel in my abdomen that occurs before I m able to ejaculate. Its a rather odd feeling that is targeted generally in the middle of my abs, and feels as if there s an internal cold blast and tingle that will stay for a couple of minutes. Ill usually still be able to feel the cold tingle for a couple minutes after ejaculating as well. I don t have any testicular pain and my skin externally doesn t feel noticeably colder to touch when im experiencing these symptoms either. Any idea of what the cause for this may be?