Apparently welders use this trick at construction sites.
Checking outlets: run an extension cord to second outlet. Poke voltage tester (one that shows 110, 220, 440 in separate LEDs) leads into nearby outlet and the extension cord female to find the pair with the highest voltage. If it is 110, both outlets are off the same side of the 220 feed line. If you get 220v readings, you may be in business provided that the extension cord can carry the amps without a significant voltage drop. You still have to have a box with a 220 outlet and two 110 inputs, plus a switch or circuit breaker.
And watch out for coils of wire, should you find the two outlets so close together that much of the extension cord stays coiled up: it is now only carrying one side of the line rather than two, and will generate a substantial magnetic field if remaining coiled.