A little birdie let me know that on Thursday, August 7th, Dairy Queen is hosting "Miracle Treat Day". If you buy a Blizzard from a participating DQ location, 100% of the proceeds (which they state are sale price minus cost of ingredients) will benefit your local Children's Miracle Network Hospital.
According to the Children's Miracle Network website, there are 170 children's hospitals affiliated with the network. Find the one closest to you here.
If you want to make sure you have the calories to spare this week, or just want to torture yourself, you can check the nutrition value of a Blizzard here ;)