Possible Clues:

• Breathless, even with one's trousers on, perhaps
• Puffed
• Breathed heavily after exertion
• Not out of trousers, perhaps, but out of breath
• Perhaps in trousers, but certainly out of breath
• What one did in trousers when it was stuffy?
• Was out of breath but into trousers, it seems
• How one needed air with trousers on, perhaps
• Seems one was into trousers but out of breath
• In trousers, perhaps, but out of breath