2002 Ford Ranger squeaks when AC is on

2002 Ford Ranger mileage: 83,000. About two weeks ago I noticed a rather annoying belt squeak. The sound came only after initially cranking over the engine, turning on the A/C, and turning the corner or steering one way or the other. The noise is quite an attention getter and usually provokes a chuckle of superiority from pedestrians and motorists. To take it a step further my beloved truck stalled at a stoplight today. It was very hot today ninety five plus degrees and again, the shrieking wild animal noises come when the A/C is on.