Can I make areas sticky so they slow down a player?

Hi

Im making a 2d game and want to have sticky patches on the floor that will slow the player down if they walk through them.

Im using a third person controller script on the player and this script controls the walk, trot and run speeds.

So is there a way of reducing these values when the player enters the sticky area to make it look like they are being slowed down by the goo?

Cheers J

My approach would be to create a box collider, and every time that the user is in this box collider you adjust the speed.