Students at most Long Island schools returned to the classroom Monday as COVID-19 cases are skyrocketing.

Some schools are taking measures to combat an even bigger post-holiday spike.

Manhasset school officials handed out 3,000 at-home COVID testing kits for students.

"I'd expect the numbers to potentially be higher again given that everybody did what they needed to do by spending time together with family," says Laura Giampetruzzi of Manhasset.

At least three school districts -- Hicksville, Freeport and Westbury are using remote learning for the first week of January due to a spike in cases from students and staff over the break.

Hicksville's superintendent said in a letter to the community that the number of positive cases over the past two days "exceeded our means to open safely for in-person instruction."

School officials say the majority of positive cases seem to be among staff and faculty.

"We know the spread is not within the school," says pediatrician Dr. John Zaso. "As we are seeing it's all from outside gatherings and parties they had during the holiday season."

In Baldwin, elementary students had in-person learning Monday while the middle and high school students were remote because of what the district described as a significant staffing shortage from positive COVID-19 cases and quarantine protocols.

Some districts handed out at home test kits with a January 2022 expiration date on the box. The FDA says that expiration date has been extended by 90 days and the kits can be used through April.