Running outside can be enjoyable. I haven’t reached that point yet and going out for my first 0°C jog didn’t really help. Apart from wearing short running socks and getting cold shins, it didn’t half feel like my lungs were suffering from the cold air. Of course, I understand that a person will suffer from frostbite long before their lungs would ever actually freeze, but it sure doesn’t feel like that when you’re out there.
Longer socks seem like a suitable solution for the whole shin situation but heating up the air you breathe in without restricting airflow is a little trickier. Here’s my back of the napkin design idea; modify a personal cooling system (one with a backpack, vest and pump setup) to have a finned heatsink over a runner’s mouth, perhaps held in place with a system like that of a one-person band harmonica frame. I’m picturing Dick Van Dyke in Mary Poppins mixed with Tom Hardy from the Dark Knight Rises.
Instead of circulating ice-cooled water around the system, the pump would take water heated by the runner’s body temperature across the face grill, warming the air the runner breathes in. The practical restrictions and issues from the system would obviously outweigh any possible benefit. But what’s life without whimsy.