My Top Hatch incubator is a little over 4yr old. It is dishwasher safe, although the hottest water I've washed it with is hot tap water...so no drastic temperature changes at all. I stored it inside the manufacturers original box. I opened the box to set up my incubator & seen 4 cracks in the lid, I was *Appalled* -it had no blunt trama to the box at all....I then set the incubator up for preheating overnight. I woke in the morning & was ***DEVASTATED*** to find the top having Numerous cracks. It was room temperature when I set it up, no temperature changes at all. I'm using the correct wattage of bulb. The middle indent in the cover has a cloudy-ness to it also. The manufacturer says they've "never heard of that happening" :-/ ~Really???~ Ugh. :-/ It's not that old & has been cared for properly. Has anyone ever had this happen to their top Hatch Incubator top cover?