2000 Ford Explorer XLT

I have a 2000 Ford Explorer XLT 4x4 with 125,000 miles. I have had trouble with it overheating I had someone look at it and about a year ago they replaced the head. I am having the same problem, I am told it is the head gasket.

Do you know why it would have gone bad so quick? Or do you think it was the first job that may have been done badly?

It may have overheated again or maybe they did not carefully check the head the last time and it is not totally flat or they did not do a good job, or maybe you are just having a bad day.  It happens.

Does this engine have two heads or one?

V6 or V8, both have two heads.