You actually run more risk by eating the undercooked center than by cooking at low temperatures. The way that I cook chicken on a stove is by first cooking it at a high temperature to brown the outside, about 5 minutes a side, and then reducing the temperature and covering it and cooking it for about 15 minutes to ensure the inside is cooked completely. Before removing from the heat I usually check the fattest section and ensure that it is still not pink in the middle. The temperature required for killing the bacteria is not necessarily that high, but time has a lot to do with it. I work in the biotech industry. To sterilize things we only reach a temperature of 250 F, but have to keep it at this temperature for 30 minutes. The same does not exactly apply to foods, but you get the idea about how time is a factor not always high heat.
For sausages I do it the opposite way from chicken when frying. I first put the sausage in a boiling bath of water and cook thoroughly (again testing the center to ensure it is cooked through). Then I brown them in oil at high temperature.
I do not have a foreman grill. But I have found a link that has recommended cooking times using one.
http://www.grillmeats.com/foreman_grill.…
Generally if I am unsure about how long to cook something, I check out epicurious.com for cooking times. Personally I prefer to cook chicken in the oven, since it is more straightforward, less messy, and healthier than frying. Use a little wine, chicken broth, or water for the slow cooking piece.