Use caution when placing high tech electronics into non-climate-controlled spaces such as attics and garages.

I once set up a building-to-building wireless LAN extension, back in the days before Wifi was a thing, this was pre-802.11. I think it might have been Proxim gear, in the early 90's. Bigass directional antennas on each building's roof, with coax cables running from the antennas down into each buildings' attic, where I put the wireless routers and plugged them into the LAN. The idea was the same as the one in this thread: short coax run to the hardware for good air signal from the antenna, then I can run any CAT5 length to anywhere from there. Also, this was specialized coax for those antennas, not just RG6 or RG59, so I don't know if I could have run longer coax even if I wanted to.

I set it up in the fall (sound familiar?) and everything was fine. Then, several months later, the users in the other building began complaining about hard-to-trace intermittent connectivity issues. The weird thing was that they would start to get the connectivity problems at the same time of day, which was mid-to-late afternoon each day. Each morning when I would investigate yesterday's reported problem, everything was fine and not reproducible.

It was of course, caused by the onset of summer weather, with the afternoon sun heating up the attic of one of the buildings. It was well over 100 degrees F in there, and the router was just cooking.

I managed to stretch the coax cable a hair farther, moved the router just a bit lower, into the drop-ceiling area of the office just beneath the attic. Problem solved.