Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Unsafe for use

I got this as a Christmas present several years ago and used it to heat water for my tea and coffee. I really liked the fact that it would whistle when ready. Unfortunately, the thing just caught on fire in my microwave! I was in the kitchen, so I was able to get it out right away, but this is totally unacceptable. It started sparking on top and there's now a cigarette sized hole burned into it. I'm off to file a consumer product safety complaint after submitting this review.Do not buy! It's unsafe to use!