Certainly those temps are not enough to boil brake fluid. Keep an eye on it, and get scientific -- mine right now are the same temp as the surrounding air, but I'm leaving out the important data about why that might be.

I would not let something like this go unanswered for a month of driving. Too dangerous. I'd have the wheels off of the front checking every aspect of the caliper operation including piston retraction, and if nothing obvious surfaced, I'd put 4 new hoses on, guessing the interior of a hose split away forming an inadvertent and intermittent check valve keeping a piston from retracting.

When the problem actually occurs, or nearly does, that's when you'll find the heat.
--
Art Benstein near Baltimore

What engineers say and what they mean by it:
"The entire concept will have to be abandoned"
The only guy who understood the thing quit.