What is the literary device in this sentence lemonade was colder than an ice berg Artctic?

The literary device in this sentence is a hyperbole. A hyperbole is a figure of speech that uses exaggeration to create emphasis or humor. In this case, the exaggeration is that the lemonade is colder than an iceberg in the Arctic. This is clearly an exaggeration, as lemonade is not typically colder than ice. However, the exaggeration helps to create a vivid image and to emphasize how cold the lemonade is.