A scald is simply a burn caused by contact with hot liquid. In this case, the liquid was also moving very fast.
About.com First Aid reader johnnyr99 submitted this image of a scald from a hot pressure washer. The combination of steaming hot water and high pressure probably meant this injury took just an instant to happen.
According to johnnyr99, this injury happened in the only area of the leg not covered by shoes, pants or socks. I suppose having any of those layers covering this bare skin might have been helpful, but simple contact with hot water is enough to cause the scalding.
This wound is a good example of a second degree burn.
Any opinions expressed here are for educational purposes only and are not intended for diagnosis.