Severe foot pain? Whats the cause?

The Bottom of my foot has been killing me the last few days. Its hot itchy and painful type pain. I have to stand on my feet all day nearly everyday as I work a very big work schedule. Its really hard to undertake my work as i cant wait to get off so i can get home and just put my feet in cold water and not walk on them for the rest of the day. The pain is located along the side of my foot, the inside of my foot the heel and the ball basically its all over. What can be causing this? and what Can i do to stop it happening as I cannot Take another week of work with this pain.