Ice Swimming

I went out to lunch to hear a talk by Sarah J Weldon who lives in Kendal and is hoping to represent GB in the Ice Swimming Championships.  From a disadvantaged background, helped by the Princes Trust,  she has done some impressive stuff in her life and now writes "cozy" mysteries to fund a charity she has set up providing STEM (Science, Technology, Engineering and Maths) education to disadvantaged youngsters all over the world using Skype and Youtube vidoes.  Its a shame her presentational skills were not better and  I'm wondering what a cozy mystery is.  Is it one which makes you feel warm and fuzzy?  It also turns out she has some strange syndrome which makes her hot when she goes in cold water.  No wonder she's good at ice swimming. She also says its an excuse to eat lots of cake - you have to be well covered.