Detecting a fan left running in a very warm/cold attic?

I have four Fantech cans situated in my attic. They’re exhausting from several bathrooms elsewhere in the house. Remote fans are much quieter. My goal is to detect when a fan is activated and issue reports/alerts/trigger something if it’s left running for more than 45 minutes.

They’re currently controlled via Lutron MA‑T51MN fan timer switches. That model allows seeing and adjusting the timer duration on the face of the switch itself. I am not interested in replacing the timer switches. The rest of my lighting is all Lutron.

It’d be nice if Lutron made a timer that was compatible with ClearConnect. They’ve announced a hub expected to ship Feb/16 that would allow setting an auto-off for any of their switches. As in, configure it ahead of time to always turn off after X number of minutes. That’d be nice, but I’d still like an option to have local control integrated on it.

The fans are in two sets, but are at opposite ends of the attic. The fans in each set are about 2’ apart. There is constant 120v power available.

Given this is an attic there is some pretty wide temperature range. Not typically below 0F, but I’ve seen it hit 130F in the summer (and probably higher). So if I’m going to put something up there I’d like to avoid using the wrong thing and have the heat ruin it.

Now, I suppose I could add in a junction box on each one and use a current amp monitor. But what about vibration detection instead? Is there anything out there suitable for this situation? Monitoring the vibration of an operating fan AND surviving attic heat?

I could, if it’s advisable, put sensors on the fans and pull low voltage wire to an interior space for a module.

If this kind of thing exists I’d like to consider also using it to monitor the exhaust fan on my hot water heater (high-efficiency gas unit with a powered fan out PVC plumbing) and on my sump pumps. In those case I’m more interested in tracking their activation (and duration) not just in getting alerts.

So what’re my options that could be integrated with a v2 hub?

You could try a SmartThings Multi sensor for the vibration/acceleration. I know I have tested mine and even gently opening my door is enough to trigger it (it pauses my Sonos when there is vibration so I don’t miss anyone knocking on the door).
The multi also will work for reporting temp up there, but I don’t see anything in the multi packaged documentation about operating temp (just opened one I had sitting here to look through the booklet).

UPDATE: Just checked on the page and see nothing there, either.