Patience

Tonight at work I was noticing that when I am worn out and tired from working 40 hours in 4 days AND writing a paper and taking a final, that I lose all patience. This is a bad thing because I work with people who need me to have patience and I also tend to take things out on people who don´t deserve it one bit (Jeramie) when I am like this. Any good ideas what you do when you are this stressed out? Anything is worth a try!!