Speaker internal amp shutting off due to heat

Hello guys, 

I hope I could get some more information from your expertise. The problem is very simple.

I have 1 Martin Logan speaker that has 2 class D internal amplifier inside to power just its 2 woofers. The problem is, if the room is anywhere approximately 80 degrees F and above, the internal amplifiers would keep shutting off and on.

This problem has shown itself more than a year ago and I’ve confirmed through 100s of timea this is indeed an ambient temperature problem. The other identical speaker has no such problem in all circumstances.

So my question is, is there something specific inside the amp that is failing for it to be so sensitive to temperature? And is this something inexpensive to fix?

Additional information, I don’t play them loud at all. If it’s hot like 85F, amp would ahut off a minute after the speaker turns on. No it isn’t near sunlight. Thanks for any help.