The spider is medium size I don't know what to do with it? It been like 20 days and I have the spider in a little box.
I don't want the spider to die, please tell me what to do, because outside it's very cold. I don't know how to fee it? http://www.saguaro-juniper.com/i_and_i/insects/spiders/funnelweb_black.jpg please answer me back asap!

If its really a big spuider I would get it to a pet shop or I would take it to a park and let it go in the trees

If you found the spider outside, it should be fine outside in its natural environment. I suggest letting it free. The pet shops aren't going to take it unless it's a particular breed that's sellable, like a tarantula. Taking it to a park is a nice idea. Just let it go.