I have no issues with temp swings. When I take out the tub I just put the probe on the shelf. Opening the incubator is what causes the swings. I've also attached the probe to a shelf and that worked well too. I just like knowing what temps my eggs will be kept at and I don't trust $10 thermometers. Like everything with BPs, there are many ways to accomplish the same goal and this way works great for me.