Loot drops with the red flame over them

I keep seeing this on drops where the item will have a red flame over the top of it like when you do a mission and they provide a special weapon you can use. What exactly does that flame mean in reference to the weapon? I notice most seem to be VOT

It was actually a glitch. Regular loot should not have that orange glow on it, only the special mission weapons that are temporary.

Ah OK that makes since. Thanks for the help.

Though I noticed that the red flame happens on weapons with elemental attribute.