pretty chilly down here too, thinking bout stepping up my basking wattage for the next few days, my cages are inside my apart. so the night lows wont get as bad as you outsiders.
i think it would be hard to confuse the two but here's an interesting article about the longlegs venomous MYTH.
http://spiders.ucr.edu/daddylonglegs.html
water is all you need, carefull to not use too much water or the chow will become runny, and hence the poo of the silkies will be runny and nasty; no fun cleaning that crap up.