Image from Turnbull and Asser
A proper dress shirt may be made out of any one of any number of materials, depending on taste and season. It may have any of a number of collar styles. There are even a fairly large number of options available in the cuff, although the majority of them are not to my taste. There are, however, two things on which I am dogmatic. Firstly, a proper dress shirt does not have a breast pocket. Secondly, and far more importantly, no dress shirt has short sleeves.
Why, you may ask, have I taken so strongly against two practical innovations? A breast pocket gives men somewhere to keep their pen or, if they are Don Draper, their cigarettes. Short sleeves, meanwhile, allow them to keep cool in the summer. Sadly, however, it is often the practical innovations that must be resisted the most. There is little that is, or should be, overtly practical about the well-dressed gentleman's outfit. It ought to speak of a traditional outlook combined with modern good taste and good tailoring to create a look that is no more prey to adjustments in the name of practicality than to changes in the name of fashion.
Sadly, a man who too obviously compromises his dress to make his life easier or more comfortable runs the risk of not being taken seriously. If you are hot, roll up your sleeves and, if you find you have nowhere to put your pen, then keep your jacket on. There are plenty of pockets in that.