As the weather warms up throughout the country, many of us start shaking off the winter blahs and come down with a different kind of malady: spring fever. So if you find yourself daydreaming at your desk, developing new crushes and spending the whole day outdoors, here’s a closer look at the science behind the sensation — and how to make the most of it as you date your way through the season.

Symptom #1: A happier, more optimistic mood

The science behind it: “One thing we really do know is that there are increases in brain serotonin in the hypothalamus from winter to spring,” says Dr. Norman Rosenthal, clinical professor of psychiatry at Georgetown University. Serotonin regulates the sex drive, eating and sleeping habits. Dr. Rosenthal also attributes many people’s happier moods to the abatement of Seasonal Affective Disorder (S.A.D.), which is a type of short-term depression triggered by increased melatonin production in the brain during long, dark winter nights.

How it affects your dating life: Shaking off rejection becomes much easier, you have more fun on dates, and you’re much more optimistic about your chances of finding The One.

Symptom #2: Feeling friskier than usual

The science behind it: “You’re being bombarded by pleasant, exciting, novel stimuli, and novelty stimulates the neurotransmitter dopamine, which in turn triggers testosterone production,” says anthropologist Dr. Helen Fisher, Ph.D., Chief Scientific Adviser for Chemistry.com and author of Why We Love: The Nature and Chemistry of Romantic Love. “Testosterone is associated with the sex drive in both women and men.”

How it affects your dating life: You feel motivated to end your exclusive relationship with Ben & Jerry/Mrs. Callender, get off your couch, and seek out human companionship instead.

Symptom #3: Increased energy throughout the day

The science behind it: Longer days increase our exposure to sunlight,which in turn reduces the amount of melatonin secreted by the pineal gland (a tiny, pea-sized gland located at the base of the cerebrum in the human brain). “There’s more daylight, so people have more energy,” confirms Dr. Sanford Auerbach, director of Boston University’s Sleep Disorders Center.

How it affects your dating life: You’re more willing to go to post-work happy hours, plan weekday dates and spend time socializing later into the evening than you normally would.

Symptom #4: You feel sexier, more confident and attractive

The science behind it: “With spring and its friend, sunshine, we’re inclined toward lighter fare,” says Dr. Trina Read, sexologist and author of Till Sex Do Us Part: Make Your Married Sex Irresistible. Lighter diets and increased activity outdoors helps many people lose weight, giving them a body-image boost. And as the temperature climbs,people shed heavy clothing and show more skin. “We say it’s more comfortable, and it is; but it’s also display behavior — the peacock quivering his tail,” says Dr. Fisher.

How it affects your dating life: As hats, scarves and coats find their way back into the closet, your overall look becomes more body-conscious — and showing off your assets often draws appreciative looks from the opposite sex. Besides, research shows that feeling self-confident makes you appear more attractive — which helps you score more dates.

So now, we’ve got to ask: do you have spring fever? And if so, where’s your fave spot to flaunt your sexy self in warmer weather? Tell us in the comments below!