Is my iPod broken? does it need to be updated?

so i got an iPod touch for christmas 2007, and since then ive tried to take care of it as best as i possibly can. i have dropped it a few times, and i dont have a cover for it. im really not a tech savvy person. so i went for a jog today coz it was really warm (im writing this question March 4, 2009) and i brought my iPod with me. it was probably 5 degrees celcius outside. i'd been out for about 4 mins and i was jogging and listening to a song, and the song finished playing, then i was waiting for the next song to come on, but it didn't. i am sure it didn't run out of battery because it was fully charged before i left the house. so im worried that either it was too cold and it froze and now its broken, or my carelessness has worn it out and it has finally broken. but i dont think it should have frozen because i've been out at bus stops on cold mornings waiting in minus 20 degrees celcius weather with windchill and snow and it has never gone dead on me. so whats the problem? does anyone know a solution to this? or what could've gone wrong?