I have a little unusual question. When Americans talk about temperature do they always use
Fahrenheit degrees or sometimes they use Celsius?

'Watch out for these babies (boilers in a plant).
260 degrees, they get hot.' What is the case here?
About 30 years ago, the U.S. powers made a feeble attempt at changing from Fahrenheit to Celsius/Centigrade. It didn't work, as old habits are hard to break. My guess in this case is that 260 degrees is Fahrenheit. Normally, in the U.S., when talking about temperatures, we assume it is Fahrenheit unless otherwise noted.
Got it! Thanks, Philip!