While it's possible that "ooshee" is a slang term or a regional dialect word, it's not a common or widely recognized word for "cold" in standard English.
It's important to remember that language can be diverse, and there are many words and phrases that are specific to certain regions or cultures. If you heard this word used, it's likely that it was a local or informal term.
To get a better understanding of its origin and meaning, you could ask the person who used it, or try to provide more context about where and how you heard it.