Yup more questions... What kind of cooler are you using? have you filled the lid with foam? Do you wrap the cooler in a blanket? Just to put it into perspective, I have a 5 gal round rubbermaid cooler. I do not use the lid... I have a round of styrafoam about 1 inch thick wrapped in plastic that I use in its place. I have one of those car windshield insulators that I wrap around the cooler... And I still wrap that with a blanket. After preheating the tun, temp is rock solid after I mash in.
Oh yea I forgot to answer your question... It wouldn't hurt to add some boiling water maybe a cup at a time, stir and check temps till you get back to where you want it.
Drinking Pumpkin ale V2, Oaked Wee heavy, The Kaiser clone, Graff, Old Jubilation clone, Sour Cranberry Ale
Carbing/Aging Westy 12, Barleywine
In the bucket None
On Deck Peach Wit, Westy 12 (19X), Pumpkin Ale 2014, FBS clone, Port oaked amber, Old Rasputin Clone, 15% RIS