Aw come on, don't feign ignorance here. What, you just HAPPENED to wind up sans Pantalones when you opened the app? Likely story. Heathen. 
Fortunately, your dignity shouldn't be too hard to recover; just restart!

Double-tap on the home button on your device, swipe up on the preview for Highrise, and then reload the app. Your avatar should appear fully clothed like a civil tenant again. 

You may be naked if we've just released an update; just give your app a second or two to finish downloading, and you'll be okay! 

Restarting not working? 
Contact us in-game or shoot us an email! Be sure to let us know what you SHOULD be wearing by visiting your inventory and checking out your equipped items.