[fmader]

First off, very nice thermometer. I have the same one and would recommend it to anybody. Long stem and cheap. But it concerns me that you are losing enough heat to be focused on checking the temp. I mashed in two weeks ago and it was 4 degrees out. I lost 1 degree in 60 minutes. I mashed I. Yesterday at 37 degrees out and lost .4 degrees in 90 minutes. It must be because mine is blue 

[eck316]

Just my two cents, when I started out, ( many moons ago) I too was worriedabout mash temps, and like most I was using a good old rubber tun. My solution was simple. Drilled a hole in the lid, stuffed the lid with foam, inserted my thermometer, sealed it up with fda approved silicon. Never worried about it again.