Both. They scorch & cook them! It is the easiest way to get your nice suit or pants shiny and ruined. Suits and pants need the right temperature (not too hot) and a pressing cloth.
I will send out shirts on long trips, but I expect more wear and tear on shirts.
By the way I always ask my local cleaner to give my clothing a "soft pressing" with a pressing cloth. They actually listen to me and the results show. I hope you can find a local cleaner like that too.