CHESAPEAKE, Va. (WAVY) — Santa says don't take the flu lightly. In this case, it's Thomas Santa, a family nurse practitioner at Patient First on Battlefield Boulevard. The Centers for Disease Control's latest map of the flu season has Virginia now in the moderate category, up from low a week ago. "After Thanksgiving, the flu season is on," Santa said in a Monday afternoon interview. "We're seeing a lot of people who are really sick with it right now. Fortunately, though, we're not seeing a lot of people who are critically ill, and I'm not having to send may people to the hospital." Here are the symptoms: sudden onset of fever, chills, and body aches. "Patients are telling me they felt like they've been hit by a truck," Santa said. Those with conditions such as kidney disease and diabetes, as well as the elderly, are at higher risk for the flu to do more damage. "Anything that makes you get sicker quicker," he said. Santa advises people to exercise their lungs regularly to keep the flu from turning into pneumonia. "Take some deep breaths and keep moving your lungs and expanding them. Just cleaning out your lungs and taking 20 deep breaths every hour — really expand them and getting the yucky stuff up." The CDC estimates 28,000 Americans died from the flu last season.