Schools For Health

20 Questions to Ask before Sending your Kids Back to School

Getting kids back to school must be a national priority.

The risks to students from school closures, including “virtual dropouts”, lack of food security, safety, and adverse impacts on social, physical and mental health, must be weighed against risks from being back in school. The scientific evidence to date about COVID-19 tells us that kids are:

  • less likely to get infected than adults
  • less likely to suffer severe effects if infected
  • less likely to transmit to others (particularly true of those aged 0-9 years old)

There is no such thing as “zero risk” in anything we do, and certainly not during a pandemic. There will be some risk to students, teachers, staff, and families. As such, it is important to reduce these risks to the extent possible.

Returning to school should not be “school as usual.” While we offer some insight into the responses you might receive, and expect, each school’s response will be different because there is no “one size fits all” plan for COVID-19.

For more details, we encourage you to read the full report.

We prepared the following set of questions as a guide for parents, teachers and school staff who may not be sure what to ask or look for at their school.

Why It Matters

The number one best way to reopen schools safely is to do so when community spread of the virus is low. Faculty collaborators across several Harvard schools, including experts in education, public health, medicine, and ethics, created a guidance document for schools and schools districts with color-coded risk levels based on the number of cases in an area and other metrics. For each color-coded level (Red, Orange, Yellow, Green), there is guidance on whether schools should open, and, if so, which age groups should be prioritized. Click here for risk levels, and color-coded map of daily new cases around the country.

Why It Matters

Research shows universal mask wearing, even of homemade masks, significantly reduces the risk of COVID-19 transmission. Because transmission can happen even when one is physically distant from others, masks should be required for everyone on school property – students, teachers, staff, and parents. Masks should also be required on school buses. Schools should have plans to enforce mask wearing on campus and on buses.  

To address mask fatigue, “masks breaks” throughout the day may be scheduled during times when transmission risk is relatively lower, such as quiet reading time or outdoor recess. However, during times when a teacher or students are talking and when students are in contact with individuals outside of their class (e.g., in the hallways), masks should be worn. Some schools may exempt preschool and kindergarten students, who may find mask-wearing more difficult. In these cases, extra care should be taken to implement other control strategies, like higher ventilation rates, better filtration, and group distancing to minimize contact with other classes and students at the school. 

Proper mask-wearing hygiene and cleaning procedures are important for effective use. Schools should follow guidance from the Centers for Disease Control and Prevention (CDC) and advise students and families on how to care for masks (e.g., clean). If there are concerns about parent, student, or teacher ability to obtain and care for a mask, the school should make them available to everyone.

Why It Matters

Washing hands is an easy and effective way to reduce transmission. All students and staff should be trained in proper hand washing/sanitizing procedures, and signage should be placed at sinks to reinforce appropriate hand-washing technique and duration. Hands should be washed with soap and water for 20 to 30 seconds upon arrival and before and after touching shared surfaces, eating, touching the face, recess, physical education, and transitioning between classes. While handwashing with soap and water is best, hand sanitizer containing at least 60% alcohol is an effective alternative when handwashing is unavailable. Hand sanitizer or portable hand washing stations should be available throughout the school. Other strategies the school may implement include installing no-contact infrastructure (like touchless sinks).

Why It Matters

Physical distance helps reduce the risk of infection by large droplets transmitted between individuals (for example, from sneezing or coughing), and is particularly effective when combined with wearing a mask. The goal is six feet, where possible, but we note that the American Academy of Pediatrics, in their guidance on re-opening schools, highlights evidence that three feet may be sufficient, particularly when masks are worn. Also factored in are the lower likelihood of kids catching, and transmitting, the virus. Further, strict adherence to six feet distancing may limit in-person instruction, and must be weighed with the risks of kids staying home.

Schools should ensure that maximum physical distance is maintained whenever possible- including in the classroom, bathrooms, and hallways, and on school buses (see more info on buses in Question 12 and Questions 19 and 20 about recess and athletics). Strategies such as spreading desks out in the classroom, staggering bathroom breaks or class transition times, limiting or discontinuing locker use, and marking one-way lanes for travel will help facilitate physical distancing. School arrival and departure times can also be staggered to decrease crowding at doors and outside the building. 

Since space can be limited, some schools may remove excess furniture from classrooms and/or modify their attendance policies to reduce the number of students in school at a given time (e.g., half of students attend school every other day) to allow for physical distancing policies. Schools may also group students by class or in smaller groups, and allow students in those groups (sometimes called “cohorts”) to be nearer to each other than six feet. While not as effective as complete physical distancing, this must be weighed against the risks of keeping kids out of school. Cohorting students can reduce the risk of a large outbreak if a student becomes sick by decreasing the number of other students with whom they had close contact.

Why It Matters

Tiny particles that contain the COVID-19 virus can float in the air, potentially infecting someone that was never in close contact with an infected person. 

Bringing more “fresh air” into a room/building can dilute particles that contain viruses and reduce the risk that someone would breathe in enough virus to become infected. Schools may rely on mechanical or natural ventilation to bring fresh air into the building.

“Mechanical ventilation” systems forcibly bring in outdoor air and distribute it throughout the building. There are established standards for the amount of fresh air coming into the building that schools should meet or exceed (called the ASHRAE 62.1 2019 – Ventilation for Acceptable Indoor Air Quality Standards). When possible, schools should increase the amount of outdoor air brought into the building beyond this standard. All re-circulated air should pass through a high-efficiency filter (see Question #6). Schools should also consider keeping the ventilation system running even outside of normal school hours (e.g., when janitorial staff is there, extracurricular activities, arrival/departure). 

If the school relies on “natural ventilation,” then the amount of outdoor air coming in can be increased by opening classroom windows or other mechanisms (e.g., roof ventilators). Window fans or box fans positioned in open windows to blow fresh outdoor air into the classroom via one window and indoor air out of the classroom via another window may help to sustain and increase fresh air in the classroom.

Importantly, ventilation systems do not always work as planned so schools should also “commission” their systems to ensure they are working properly and may want to monitor ventilation rates or air quality throughout the school.

Note that the control strategies in Questions 5, 6, and 7 are effective at controlling airborne virus particles and recommended as first priorities. Some schools may not be able to only rely on increases in ventilation or filtration. There are a large number of other unproven or less proven technologies now being marketed. Please refer to the Healthy Buildings section of the main report for more information.

Why It Matters

Mechanical ventilation systems can use a filter to remove small respiratory particles that contain viruses in air that is recirculated through the building, but some filters work better than others. Filters are rated using a “MERV” rating system (also by ASHRAE, the people who publish the ventilation standards) that indicates the percentage of particles and the sizes of particles that filters can remove from air passing through them. Schools should consider replacing filters with those rated MERV 13 or higher, since filters with these ratings are able to significantly reduce concentrations of particles that carry viruses in the air that passes through them. However, some systems cannot handle this type of filter. In this case, other approaches may be useful (e.g., see Question #7 about portable air cleaners). Filters should be checked regularly to make sure there is proper fit (properly sealed around the edges so air does not  leak through other openings beside the filter itself) and airflow through the filter.

Why It Matters

Portable air cleaners with high-efficiency particulate air (HEPA) filters may be useful to reduce exposure to viruses emitted from infectious individuals. However, devices have to be the right size for the room and placement should be carefully considered. For a standard classroom, one useful metric is the “Clean Air Delivery Rate” of the unit, or CADR, which should be about 100 cubic feet of air cleaned per minute (cfm) per 250 square feet. (CADR can be measured differently, so look for the CADR for ‘smoke particles,’ rather than dust or pollen, because smoke particles are smaller.)

Great care should be used when replacing filters in portable air cleaners, as active viruses may be present on the filter. Filters should be replaced when classes are not meeting by a person wearing goggles, a mask, and gloves. The filter should be removed carefully and placed in a large tie-off garbage bag with immediate disposal. 

Why It Matters

Plexiglass shields may help prevent the spread of virus present in large droplets, such as those generated when one coughs or sneezes. These barriers may be particularly useful when physical distancing is hard to maintain and in areas where there are repeated, and fixed, interactions, such as reception desks and cafeteria cashier. Some schools may also consider installing plexiglass between students’ desks or between the teacher and the class. Even when plexiglass shields are in place, it is still ideal to require everyone to wear masks.

Why It Matters

School arrival, departure, and class transitions can be a higher-risk time due to the potentially large number of people in close contact in school entrances, exits, and hallways. Schools may consider staggering arrival and departure times so that children in different classes are not all entering or exiting the building at the same time. Even a difference of 5-10 minutes for each class or grade level could greatly reduce the number of students in the hallway heading to the door for dismissal at one time. Students and staff should be encouraged to not loiter in entrances, exit areas, or hallways, but if waiting is necessary, lines should be clearly marked to maintain physical distancing. In small hallways or stairwells, clearly marked paths on the floor that indicate one direction of travel could be used when possible. Additionally, different doors could be used by different classes or grades to enter and exit the school to minimize crowding and to reduce the number of people touching the same doors.

Why It Matters

In order to maintain physical distancing without greatly reducing the number of students in school at the same time, schools may consider teaching in spaces not typically used as classrooms (e.g., cafeterias, gymnasiums, auditoriums). Schools may also hold classes outdoors which can help reduce the spread of the virus due to dilution of airborne virus particles and ability to physically distance. During the fall, students and teachers can wear sweaters or light jackets to continue holding classes outdoors. If a tent is used, however, it should either have no walls or screened walls to allow sufficient ventilation. 

In place of holding lunch in a traditional cafeteria, students may eat lunch in their classrooms. School-provided lunches may be prepackaged and brought to the classroom to prevent crowding in the cafeteria. Lunch may also be held outside, weather-permitting. If the cafeteria must be used, students should maintain physical distance or be separated from one another using plexiglass shields to reduce transmission during a time when masks must be removed. Again, some schools may allow students in the same class or cohort to eat together but should maintain distance between classes or cohorts.

Why It Matters

COVID-19 can be transmitted when someone touches a surface that has been infected (e.g., coughing/sneezing on the object or on their hand before touching the object) and then touches their eyes, nose, or mouth before washing their hands. This is called ‘fomite’ transmission. Schools may consider purchasing additional sets of shared equipment (e.g., coloring supplies, calculators, balls/toys) to reduce the number of shared objects. Frequent cleaning, particularly of high-touch surfaces, can help prevent this type of transmission but schools should use products approved by the Environmental Protection Agency [the list of approved products is called List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19)]. Cleaning products can pollute the air, so deep cleaning should be done outside of normal school hours and care should be taken to open windows or maintain high ventilation rates to protect staff and students.

Why It Matters

Masks should be required while on the bus, all windows should be kept open, and frequent cleaning policies should be implemented. Schools may also consider supporting increased reliance on other safe modes of transportation (e.g., walking, biking) to reduce reliance on school buses. Efforts should be made to reduce the number of students on each bus to allow for physical distancing (although this may not be feasible due to the increased number of buses needed). Plexiglass barriers between students and around the driver may be useful when this is not feasible.

Why It Matters

While the school community must assume a shared responsibility for safety, a person or team should be appointed to lead the COVID-19 response. This person should have a plan that ensures that information is quickly and accurately shared between the school administration, teachers, parents, students, and community members. They should also be a person parents can contact with any questions or concerns about the school’s plan.

Schools should provide frequent communication regarding school policies through a variety of mediums. These communications should be accessible to everyone in the school community, which may require translation into multiple languages, physical copies of information or phone calls in addition to online distribution, and frequent reminders of policies. Additionally, communication should be in accessible language that does not require an advanced reading level to understand policies and procedures.

Why It Matters

Schools should design clear plans for what the policy will be in the event of a student, teacher, or staff member infection. This will require a contact tracing protocol, which may be developed in partnership with or by the local board of health. A rapid communication plan to inform parents, teachers, and staff members of infections in the school is needed. However, schools also have to follow the guidance of the Family Educational Rights and Privacy Act (FERPA) to protect student and staff privacy.  A testing protocol may also be developed to refer individuals who present with symptoms or who may have been exposed to testing centers following local guidance. Schools should have clear guidance indicating when students and staff should quarantine or isolate and when they are allowed to return to school. Schools must frequently update their plans as the number of cases and hospitalizations changes in the surrounding community, and be prepared to re-close if necessary without long breaks in providing education and other vital services, such as meals and student support.

Why It Matters

To reduce transmission in schools, it is vital that no student, teacher, or staff member comes to school while sick. Education about COVID-19 protocols and symptoms should happen through a variety of channels to ensure everyone is able to receive the information (e.g., flyers/signs, letters, virtual meetings). Parents may be asked to confirm that their student is not sick before school each day, and teachers may be asked to self-report their own symptoms. Adults in the school should be trained to recognize the symptoms of COVID-19, and schools should have a plan to isolate individuals who present with symptoms. Additionally, schools may implement temperature or other (e.g., ability to smell) checks to identify potential cases. School policies regarding attendance requirements may be changed to reflect the seriousness of COVID-19.

Why It Matters

Individuals may be home temporarily to quarantine or longer-term because they are at high-risk for serious complications from infection. Schools should implement plans to support all students, teachers, and staff who are learning or working from home. This may include providing technology, meals, or other support services typically available in school.

Why It Matters

Schools may be implementing other policies to reduce risk. For example, nonessential visitors may be restricted to decrease the risk of an infected individual entering the building. Parent-teacher conferences and administrative meetings should be held virtually. Schools may need to hire additional staff to adapt to new supervision and cleaning regimens and to teach students in smaller classes.

Why It Matters

Activities such as singing, playing a wind instrument, yelling, screaming, or breathing heavily increase particle emissions from the respiratory system and therefore increase transmission risk. Moving these activities outdoors, reducing group sizes, maintaining physical distance between students and frequent cleaning are all important risk-reduction strategies. Particularly risky activities may be held online or replaced with safer alternatives.

Why It Matters

Strategies should be implemented to allow students full access to the schoolyard and all playground equipment with no reduction in recess time. Ideally, recess times would be staggered so that students in different classes could remain separate but have full use of the schoolyard during recess. Schools may either allow students in the same class to play together or may promote physical distancing (e.g., by promoting solo play or games that do not require physical proximity). Schools may increase the amount of available portable equipment (e.g., balls, hoola hoops) or allow students to sign out pieces of equipment to limit the amount of shared equipment. While direct contact with fixed equipment (play structures, like swings or slides) is likely not a major route of transmission due to virus inactivation in sunlight, increased supervision, handwashing before and after recess, and frequent cleaning of shared equipment are strategies that can reduce overall risk during recess.

Why It Matters

Being in close contact, breathing heavily, and sharing equipment increase risk of COVID-19 transmission but there may be ways to safely participate in sports. Indoor sports are riskier than outdoor sports, so extra precautions should be taken for indoor practices or games and activities should be moved outside whenever possible. Masks should always be worn by coaches and whenever possible by players (e.g., during transition times, on the sidelines). As always, the goal is to reduce the number of contacts of individuals and to maintain safe physical distances between people, so practices may be conducted individually or in small groups and huddles or team meetings should be eliminated. The number of competitions may be reduced or limited to only local teams. The accumulation of virus-laden particles due to screaming or yelling should be reduced by educating coaches and restricting spectators.


This is a joint project between scientists at Portland State University and the Healthy Buildings program at Harvard T.H. Chan School of Public Health. 

Portland State University
Richard Corsi
Elliott Gall
Andrea Gall

Harvard T.H. Chan School of Public Health
Joseph Allen
Kimberly A. Clevenger
Jenna Lang
Emily Jones
(on behalf of the Harvard Healthy Buildings program team)


This document is provided for informational and educational purposes only. It is intended to offer guidance regarding questions about best practices regarding the general operations of buildings in an effort to reduce the risk of disease transmission, specifically novel coronavirus SARS-CoV-2 and the disease it causes, COVID-19. Adherence to any information included in this document will not ensure successful treatment in every situation, and the user should  acknowledge that there is no “zero risk” scenario, that each building and situation are unique and some of the guidance contained in the document will not apply to all buildings, or countries outside the United States.

Furthermore, the document should not be deemed inclusive of all proper methods nor exclusive of other methods reasonably directed to obtaining the same results. The document is in no way intended to override or supersede guidance from government and health organizations, including, without limitation, the Centers for Disease Control and Prevention, the World Health Organization, the United States Government, and or any States. The information contained herein reflects the available information at the time the document was created. The user recognizes that details and information are changing daily, and new information and/or the results of future studies may require revisions to the document (and the general guidance contained therein) to reflect new data. We do not warrant the accuracy or completeness of the guidance in this document and assume no responsibility for any injury or damage to persons or property arising out of or related to any use of the report or for any errors or omissions.