Look at pictures of sick people.

Via The Consuming Instinct: What Juicy Burgers, Ferraris, Pornography, and Gift Giving Reveal About Human Nature:

Being exposed to photographs of individuals spreading their germs (e.g., via sneezing or coughing) is sufficient to elicit a boost in one's immunological defense system.

It's legit. Here's the study he's referring to:

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An experiment (N = 28) tested the hypothesis that the mere visual perception of disease-connoting cues promotes a more aggressive immune response. Participants were exposed either to photographs depicting symptoms of infectious disease or to photographs depicting guns. After incubation with a model bacterial stimulus, participants' white blood cells produced higher levels of the proinflammatory cytokine interleukin-6 (IL-6) in the infectious-disease condition, compared with the control (guns) condition. These results provide the first empirical evidence that visual perception of other people's symptoms may cause the immune system to respond more aggressively to infection. Adaptive origins and functional implications are discussed.

Source: "Mere visual perception of other people's disease symptoms facilitates a more aggressive immune response." from Psychol Sci. 2010 May;21(5):649-52. Epub 2010 Apr 2.

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You looked at the picture above, right? Your immune system is already stronger. You're welcome.

There are a number of other simple research-based tips for staying healthy and dodging illness:

• A dog can be better for your health than a spouse. Doesn't even need to be a real dog: Petting a stuffed dog has positive effects on the immune system.

• Exercise boosts immunity.

• Stress can make you sick so know what to do to reduce it.

• Writing can improve your immune system and even speed the healing of wounds. 

• Get enough sleep. Seriously, sleep is a miracle cure. Yes, I know you're a night owl. Fine, take a nap.

• Get happy. Here's how. Be optimistic. Stop being bitter.

• If you're going to be seriously ill, do it now, not in July and never over a weekend. 

• Go to a nice doctor because they'll heal you faster.

• I can give you a prescription that will reduce symptoms of illness, make other medication 4x as effective, improve strength in the gym and even increase libido... It's called placebo. Did I ruin it by telling you it's not a real drug? No, because placebos still work even when you know they're placebos.

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