Help with my stubborn dog?

I have a 10 month old lab. She is a sweatheart, and i've always had a hard time with walking her, which i'm hoping she'll grow out of. But lately she has started this new thing of laying down during our walk. I don't mean like a long walk, i'm talking about the 100ft to our mailbox. I live in an apartment, and i think the boilers are messed up cause my apartment is really warm, and it doesn't help that my apartment is above the boilers, so i think she's doing it to lay on the cool gr. Which would be fine except i've got people staring at me cause she does it where i can't sit either, if there was a bench out there or something i'd let her lay down. Anyway, half the time it looks like i'm abusing my dog because nothing i do will get her up so i have to grab her by the collar to get her to stand up and then i have to basically drag her to deter her from laying down again. Please help!!!!