Gym shedule in NYC Cold

Did you NYC is getting colder? I had only heard or read about it but now ilive in NY and this is going to be my first NY winter. Till now, the weather aint that cold but later ice will be part of your life. So my worry is how will i complete my regular fitness exercise? I used to finish work by 6 and goto the gym which is in the same Goldman building which i love because i dont have to leave my office for that. After exercising, i'dlike to take a shower and there is a provision for same in the gym. But at 7 pm,its still cold outside and you dont wanna take a chance catching cold or becoming sick. As for me, i have started "running" during break hrs. I make good use of it exercising between 12-1 pm and eat my lunch then. The advantages are after 5.30-6 pm i can head straight to my home, no chance of falling sick (atleast by eve i am good to go out in winter as i have taken bath in afternoon), complete set of work and exercise together. After the 13 mile stint,i never fail to run on treadmill for 3-4 miles. This is getting little off topic now but i have a friend of mine who comes to work/gym with me. She is heavy and all she does is WALK on the treadmill. I know how hard i have tried to run that 13 mile and here i see a young gal WALKING on the treadmill. What on earth does she think that walking will help her shed 40 pounds? With that much to reduce,the schedule i'll give to somone will be very strenous and my advise to her didnt work. I feel more pity on her than overweight gals in India cuz she is exposed to American lifestyle and culture but in vain. Probably the guy whom she intends to marry and perhaps for whom al lthis is being done will have an effect on her.....