Instruct: Classify the given review into positive or negative sentiment.
Query: Short life span

This worked great for about four months and then it started getting very erratic readings even just turning it on. The first time it started acting weird is when I went to test a piece of pork and it said it had an internal temperature of 230 degrees! Then without using it and just turning it on, it gave me a reading of minus 3 degrees. I'm very disappointed in this thermometer.