Setting Your Thermostat

Finding the right temperature for mood and expression requires careful adjustment. As soon as you think you have the dial set on "healthy," you may need to turn it a notch:

• If you feel angry or frustrated, speak out.

  Social repression is associated with a lower killer T cell count and more difficulty fighting infection. (AIDS patients who hide their homosexuality have lower T cell counts and get sicker than those who reveal theirs.) But do express yourself nicely: Hostility may increase risk of heart disease and stroke.

• When sick, relax.

  The moderate stress of daily life aids immunity, but when you're sick, you're already under too much stress and don't need more. When fighting active illness, try to alleviate the stressors that normally keep you stoked.

• A spat with your spouse can be like a run in the park.

  After married couples spent 15 minutes discussing contentious topics, blood pressure and heart rate increased and killer T cells surged in patterns resembling those observed during moderate exercise.

• Sex differences matter in battle.

  Wives are more likely to experience hardening of the arteries when they bring hostility to an argument—and the risk rises further when a partner is hostile, too. Husbands' arteries don't harden with hostility but rather with issues of dominance—when either partner acts controlling during fights, mens' hearts are placed at risk.