Dear Doctor: A few years ago, you had a column about why it’s important to know CPR. My boyfriend took the Red Cross class, and he actually ended up helping someone once. But what about now, during the pandemic? Is it safe to give or get CPR?

Dear Reader: Considering that a main avenue of transmission of the coronavirus that causes COVID-19 is believed to be respiratory droplets from an infected person, your question about CPR is a timely one.

For anyone unfamiliar with CPR, which is short for cardiopulmonary resuscitation, it’s an emergency procedure performed when someone’s heart has stopped beating. This can occur for many reasons, including heart attack or cardiac arrest due to near-drowning, an extreme allergic reaction, asthma attack, smoke inhalation or poisoning. When initiated at the start of a medical emergency, CPR can double, or even triple, someone’s odds of survival.

The process is made up of three distinct components. First, call 911 and report the emergency. The other two elements of CPR are chest compressions, which are performed on the sternum in a specific rhythm, and mouth-to-mouth rescue breathing. The challenge during the pandemic is the proximity that is required to perform CPR. The rescuer is literally on top of, and just inches away from, the person they are helping. Even without the element of rescue breathing, an exchange of breath during the CPR process is likely. Regarding rescue breathing, only someone who is formally trained in CPR should attempt it. And during the pandemic, the Red Cross advises against performing rescue breathing when COVID-19 is either suspected or confirmed.

This leaves chest compressions, which still put people into far closer proximity than the 6-foot distance guidelines we’re all trying to adhere to. To keep both parties as safe as possible from the airborne respiratory droplets or aerosols, the Red Cross has outlined specific procedures. The person performing CPR should wear as much personal protective equipment as possible. This includes respiratory protection, eye protection, disposable gloves and a disposable gown or covering of some sort. Although N95 masks are optimal, they remain in very short supply. A properly fitted mask made of multiple layers of fabric is an acceptable substitute. The person receiving CPR should be outfitted with a mask as well. If only one mask is available, the Red Cross recommends using it on the victim.

Part of performing CPR is assessing whether or not the victim has begun to breathe on their own. At this time, the Red Cross is asking rescuers to do a visual assessment rather than listening or feeling for breath. Taking this precaution can decrease the risk of transmission of the virus. People trained in CPR have been taught that using rescue breathing when cardiac arrest follows a breathing problem, such as choking, a drug overdose or near-drowning, often leads to a better outcome. However, due to the risk of viral transmission, it is now recommended that compression-only CPR be administered until paramedics arrive in response to your 911 call.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I saw on the news that if you work out for 11 minutes a day, you are protected from the bad stuff that happens from sitting too much. Is that really true? I’m stuck at my desk all day, and that’s not changing anytime soon.

Dear Reader: We think you’re referring to a recent study, published in the British Journal of Sports Medicine, which looked at the health outcomes of people whose lifestyles ranged from extremely sedentary to moderately active. According to the findings, even a small amount of daily exercise helped to mitigate the negative health effects of prolonged inactivity.

The conclusions outlined in the study caused quite a splash and have since popped up on TV, newspapers and magazines. And small wonder: Several years ago, research linked prolonged sitting -- that’s eight hours or more per day -- to an increased risk of premature death. With so many jobs, like your own, now tethering workers to their desks, people have become eager for information on how to lessen the ill effects.

This new research, which reexamines data collected in nine previous studies, focused on about 44,000 people who each wore an activity tracker to accurately monitor their daily movement. The participants, who were middle-aged and older, remained seated an average of 10 hours each day. When they did exercise, it consisted of short sessions -- eight to 35 minutes -- often simply walking at a moderate pace.

When the researchers looked at mortality rates in the years after the participants enrolled in the studies, they found the expected link between the people who exercised the least and an increased risk of premature death. The surprise came when quantifying just how much exercise it took to reverse the trend toward an earlier death. The answer was the 11 minutes of daily exercise that grabbed your attention in the news story you saw. It’s important to note that those 11 minutes of exercise did not, as you said in your question, completely erase the ill effects of prolonged sitting. However, the findings of the study do suggest that even a small amount of exercise appears to confer health benefits.

An important conclusion in the study, which headline writers didn’t get quite so excited about, is that the magic number when it comes to exercise appears to be 35. That is, the greatest benefit comes when someone engages in moderate exercise for at least 35 minutes per day. That’s actually in line with the current guidelines put forth by the Department of Health and Human Services. Specifically, at least 150 minutes of moderate aerobic activity, or 75 minutes of vigorous aerobic activity, spread out over the course of a week. Interestingly, several studies have suggested that those 35 minutes of exercise don’t have to happen all at once. Rather, they can be split up into several sessions throughout the day and still yield a similar benefit. That’s encouraging news for people who think they don’t have time to exercise. Let’s all celebrate by getting up out of our chairs right now and taking a brisk 10-minute walk.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My boyfriend and I live in northern Ohio, and I think we have that thing where you get depressed from not enough light. He’s kind of skeptical, but I really do think it’s happening. Can you describe the symptoms? Is there anything we can do?

Dear Reader: You’re referring to a condition known as seasonal affective disorder, or SAD. Sometimes referred to as the winter blues, it’s a mental health condition that has been linked to the shorter days and longer nights of the fall and winter seasons. Although the exact causes aren’t yet known, researchers have explored several hypotheses. These include the idea that reduced levels of sunlight have an adverse effect on circadian rhythms, on levels of the brain chemical serotonin or on the hormone melatonin.

There’s also a link between distance from the equator and incidences of SAD. People living in the northern reaches of the United States, as you do, are at greater risk of developing SAD than those in the southern part of the country.

It’s estimated that up to 20 million people in the U.S. experience some degree of seasonally related depression each year. Symptoms often begin with autumn’s annual double whammy of shortening days and the end of Daylight Saving Time. They intensify throughout the darker months of winter, then ease up again in the spring. Symptoms include persistent low mood, lethargy, lack of energy, sleep disruption, irritability, loss of interest in daily activities, feelings of hopelessness, difficulty concentrating, anxiety or weight gain. Episodes of SAD can begin with symptoms that are mild, but which gradually intensify. In some cases, symptoms can become severe enough to interfere with daily life.

If you suspect you may be experiencing seasonal affective disorder, you should see your health care provider. Several other medical issues, such as thyroid conditions, anemia or clinical depression, can present with symptoms similar to SAD. Diagnosis involves a physical exam, including a detailed discussion about symptoms relating to mental health. In order to rule out thyroid issues, a blood test may be performed.

For people diagnosed with SAD, treatment can include light therapy, psychotherapy or medication. Light therapy is just like it sounds -- deliberate exposure to bright light. The individual sits in front of a specially designed light box for 30 to 45 minutes each day. These devices are made to filter out damaging UV rays. However, since they are up to 20 times brighter than natural light, they may not be right for everyone. People with certain eye conditions, or who take medications that increase sensitivity to light, must be under medical supervision to use light therapy. Psychotherapy, or “talk therapy,” offers a time and place to share feelings and to learn coping techniques. Medications that affect serotonin metabolism can also be helpful.

Meanwhile, be kind to yourself. Try to spend some time outdoors each day, get regular exercise and eat a healthful diet. Keep screen time to a minimum. And if symptoms persist when the sunlight returns, be sure to tell your doctor.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)