How exothermic are your fermentations?

Has anyone ever accurately observed/ recorded how much heat a carboy or plastic bucket can give off? (say, sitting in a room that is around 68?)

I've noticed that it depends on how vigorous the fermentation actually is. And it seems like the hotter it gets, the faster it goes, so the hotter it goes.

I've been keeping my fermenters pretty well controlled for the last three years or so, but even yesterday I noticed that my room was 59 degrees and one fermenter was chugging away at 66 degrees, while one was more slowly fermenting at 62 degrees. (Both are fine at those temps, so I left them there).

10 deg it the biggest differential I have seen, but as YooperBrew stated it does depend on the vigor of your fermentation. some yeasts are very fast and aggressive. others are a sunday drive.

some of my higher temps have been a result of washing and reusing a yeast cake.

I just wired up a single stage Love to a new mini fridge, and im going to ferment in it and serve in it.
Just like alot of the other tips and tricks, i realized why people may opt for dual stage contol. I thought I'd be ok, but the room and temp probe are reading low 60's or so. Im wondering if i get a fermentation going, will that be enough to at least bump the ferm bucket up to 68-ish? Im planning to brew a Pale Ale today, and re-pitch WLP001. I'd hate for the temp to be too low to start/complete fermentation.

I think you'll be just fine in the low 60s.