Why does a small LCD fade when warm?

[georgeNCSUee]

I have a VW Golf4 that has a small LCD in the center of the instrument cluster and it fades when warm. For example it's nice and bright at night but in the middle of the day when it's warm inside it's faded and you pretty much can't see anything. It's one of those LCDs that's dark when off and lets the backlight through when on. What makes it fade like that and can it be fixed without having the replace it (since I haven't been able to find a replacement anywhere)? I appreciate any replies.

Here are some pics of the part if that helps:

[kenray]

are you sure it's not the sunlight that makes the lcd seem dim. sometimes the sunlight overpowers the backlight of the lcd.

[georgeNCSUee]

It's not the sunlight. While it was cool and bright one time, I warmed it up a bit with the heat gun and it faded and turned dark.