Always Reading HI

Have you checked the MANUAL? 

They have a lifetime warranty.  Set up an RMA with Exergen and they will send you a replacement.

^^^Chris is correct.  In fact, ANY issue with the thermometer is covered.  Once I got one with a broken battery cover and called Exergen to see how to order a replacement.  I was told that they don't sell parts (even the battery cover!), but would exchange the entire thermometer under the lifetime warranty.