The Gauntlets of Flaming Fury, a magic item from the WoTC adventure Baldur's Gate: Descent into Avernus, have the following property amongst others:
While you wear both of these steel gauntlets, any non-magical weapon you grasp with either gauntlet is treated as a magic weapon.
Would those Gauntlets make Improvised Weapons be treated as magical?
Reminder on Improvised Weapons rules:
Sometimes characters don't have their weapons and have to attack with whatever is at hand. An improvised weapon includes any object you can wield in one or two hands, such as broken glass, a table leg, a frying pan, a wagon wheel, or a dead goblin.
Often, an improvised weapon is similar to an actual weapon and can be treated as such. For example, a table leg is akin to a club. At the DM's option, a character proficient with a weapon can use a similar object as if it were that weapon and use his or her proficiency bonus.