Fever brings in the lymphocytes

“In whatever part of the body there is a sweat, it shows that the disease is seated there,” said Hippocrates. Now, Qing Chen, Sharon Evans (Roswell Park Cancer Institute, Buffalo, NY), and colleagues find that fever turns on homing molecules that direct lymphocytes into lymph nodes. The increased trafficking through lymph nodes should increase the chance of a lymphocyte encountering and being activated by its target antigen-presenting cell.

Higher temperatures are known to be beneficial for postinfection survival. Cold-blooded animals do better if they can seek out the sun when infected. Infected warm-blooded animals incur a 15% increase in metabolic cost for every 1°C rise in core temperature, suggesting that the benefit may be equally high.

The most obvious response to fever is that vasodilation (an attempt to cool down the body)...