According to Julee Rosso, author of The New Basics Cookbook, beef is considered rare when it is 130 degrees at its thickest point and when the center is red or dark pink. While some recipes, such as steak tartare, call for barely cooked or uncooked beef, eating your steak rare can have health effects that you might not want to encounter.
If your steak is undercooked, you are at risk of contracting one of several foodborne illnesses. These conditions may be caused by E. coli, salmonella or other bacteria, and they are often referred to generally as "food poisoning." Symptoms of food poisoning include nausea, vomiting, diarrhea, abdominal cramps and fever. Prolonged vomiting and diarrhea can cause dehydration, shock and, rarely, death. Young children, pregnant women and the elderly are particularly at risk for complications.
Eating rare steak during pregnancy can lead to a miscarriage or stillbirth if the meat is contaminated with listeria, toxoplasmosis or if another bacteria causes severe illness. Listeria may be present in uncooked or undercooked meat and can cause flu-like symptoms, headache, nausea and vomiting in the pregnant mother. Toxoplasmosis is caused by a parasite and may not cause symptoms in the mother, but it can lead to blindness and brain damage in the unborn baby.
Steaks should be cooked to a minimum of 145 degrees Fahrenheit at the center point or to medium-rare, according to the U.S. Department of Agriculture. Keep uncooked meat separated from cooked or ready-to-eat foods. Wash your hands right away after touching uncooked meat, as well as any utensils or dishes that touched the meat before it was cooked. Wrap cooked food and place it in the refrigerator or freezer if you are not serving it right away. Do not eat any food that has sat out at room temperature for more than two hours.
If someone has symptoms of food poisoning after eating rare steak and they are very young, very old or pregnant, seek medical assistance right away. If you notice bloody diarrhea, call your doctor. The symptoms of severe dehydration include dry mouth, scant urine, sunken eyes, increased heart rate and rapid breathing. If these occur, seek emergency medical treatment. In some cases, these complications may require hospitalization.