White blood cells also make chemicals that cause a fever. A fever is a higher-than-normal body temperature. Normal human body temperature is 98.6°F (37°C). Most bacteria and viruses that infect people reproduce fastest at this temperature. When the temperature is higher, the pathogens cannot reproduce as fast, so the body raises the temperature to kill them. A fever also causes the immune system to make more white blood cells. In these ways, a fever helps the body fight infection.
Context: Jim and Pam are a married couple who both have the same illness. They are at home from work today and are in the process of taking their temperatures so they know if they need to go to the doctor or not. After using the thermometer, they learn that Pam has a much higher fever than Jim. They decide they should take Pam to the doctor to get her looked at.
Question: The bacteria is reproducing faster in which person?