How about propagation delay by temperature? (device: EP2C35F484I8N)

[Altera_Forum]

The "EP2C35F484I8N" device is used my project. It is very good working on low temperature about 20'C, but is not working on high temperature about 45'C. 

Why not working on high temperature? What is difference points on low temp vs high temp?  In my opinion, may be, this result is caused by propagation delay on temperature and async coding style.  On high temperature, "Action trigger signal" is LOW, always. (QuatursII 12.1's time options is default setting.)  https://www.alteraforum.com/forum/attachment.php?attachmentid=9329  < Figure 1. Coding Block Diagram in FPGA >

[Altera_Forum]

Devices get slower as they heat up. With synchronous design practices and timing constraints, the fitter will try to fit your design so it meets timing under all PVT conditions(process, voltage and temperature), and TimeQuest will tell you whether it was successful or not. For asynchronous design(which could mean a lot of things), I can't say what will happen over PVT, just that delays will change.