So you work hard, you're tired and sore, it's cold out, and you just want to soak in a tub of hot water. But that damned overflow opening around the tub drain lever lets the water out so your navel and sore parts are exposed to the air and not under water. Solution? Go to K-Mart, buy the rubber business end of a sink plunger, the kind that screws onto a wood handle. Don't need the handle, just the replacement end. Get the flat-ended one, not the extended one used for toilets. Stick it over the drain lever and overflow slots, fill the tub to within an inch of the rim, and Ahhhhhhh! Probably have to store it under the bathroom vanity between soakings, wives don't seem to like it left on the soap dish.
You're welcome.