Parasites don't die at low temperatures, and it is difficult to survive at high ambient conditions, especially after boiling, steaming, roasting and cooking the food, which is usually free of parasites.

Thoroughly cooking meat, seafood and boiling drinking water can effectively reduce or eliminate parasites.

Toxoplasma gondii, for example, infects humans through meat that is not thoroughly cooked. One-third of the world's population is infected, and 50% of Germans are infected. And the French, who like to eat undercooked meat, have an 80 percent infection rate. Toxoplasma gondii, a common crescent-shaped parasite, attacks a person's central nervous system. People can get the parasite by eating undercooked meat or by holding an infected pet. Most people who have been infected with this parasite show antibodies to it, but few show symptoms. People with weakened immune systems are more susceptible to toxoplasmosis, and toxoplasmosis infection in pregnant women can have serious or fatal effects on the fetus.

Symptoms: flu symptoms, fever, chills, weakness, headache