Just moved into a 20 year old home. When using the sink in the MBR, it often takes several minutes to get cold water. Sometimes the water coming out when you turn on the cold water is very warm, if not hot. Does not appear that a hot air duct is near the cold water line. The sink has a faucet that has dual controls (one hot, one cold). Any ideas what is occurring and how to solve?

This sounds like a worn cartridge in a tub and or shower mixing valve.