You will take metformin by mouth every day at about the same time each day with a meal and cup of water (about 8 ounces). You should take it at home except on the days when you have a study visit. On study visit days, you may take the metformin before you receive the temsirolimus. Depending on your dose, you may take metformin 1-3 times daily. Your study doctor will tell you how to take this drug.