Please help me buy Ice cubes in Madurai

Hi, i'm travelling through Madurai soon, and i need to keep some things cool on the journey. I was hoping someone could tell me where i can find edible ice cubes. Seems silly to ask, but supermarkets are a hit or miss, and i wouldn't have time to hunt around. If anyone knows with confirmation where i can find some ice cubes please post. I will probably be near Kodikulam, KK Nagar, Vandiyur lake area, or Kulamangalam. But any place within reasonable distance is fine. Thanks.