well, it depends on how old you are and what the state of your immunity is, again you walk from the entrance to the car and back or make marches of 2-3 km, from my own experience I will say this: after the army, I did not buy winter clothes and shoes for 5 years , there was no car either, but then I started to catch a cold
A couple of friends have earned themselves cystitis in such a way. For the fairer sex, this can generally end in disrepair, chill your appendages. And in general, from the legs all diseases, they say. Better not to overcool.
It was one winter, and I will notice it was very cold, the temperature reached -20, and I calmly walked in sneakers in the snow, and strangely enough, I was not cold, and did not even get sick! Now I can go out warmly shod, and clatter my teeth from the cold, and end up getting sick! It all depends on immunity! But if you walk in flip flops in the cold, then frostbite and acute respiratory infections are clearly guaranteed.
During my school years in the winter I drove in ordinary summer sneakers. I could sacrifice my comfort for the sake of beauty and went to the disco in autumn boots.
The only consequence that overtook me was falling on the road with my head on the ice due to the soles not adapted for winter. I am 25. Perhaps by the age of 60 I will feel something, but so far so good.
And from the point of view of banal logic, it is quite possible to get frostbite of the feet if you walk for a long time and in severe frost.
One winter, just one, I wore autumn shoes. I was 15 years old then and so I protested against the boots my mother bought. They were terrible - two sizes larger, made in the USSR (we called them, excuse me, shitty), never fashionable and not beautiful. The result of the protest began to manifest itself ten years later. By the age of 25, I already had a diagnosis - rheumatoid arthritis. Then I said goodbye to heels above 5cm. Now I can't stand / walk for more than half an hour.