Power outages and freezing temperatures continue to throttle Texas. People without heat or safe water are heading to warming centers or gathering in the homes of friends who have the lights on. The most pressing concern for many Texans right now is keeping warm, finding food, and making sure their water is safe to drink. But in the background is the ever-present threat of COVID-19 — which could spread in those indoor spaces.

COVID-19 cases in Texas are declining right now, like they are in most of the country, but thousands of cases are still reported each day. Hospitalization rates are still high. The ongoing pandemic means that any other disaster, like the freeze, is layering on top of a baseline emergency. “It’s broadened everything into a compound disaster, where you have more than one problem happening at the same time,” says Kristina Dahl, a senior climate scientist at the Union of Concerned Scientists.

The freeze creates similar conditions to the COVID-19 risk posed by other weather-related disasters last year: hurricanes Laura and Delta. Both hit Louisiana and other parts of the Gulf Coast in a one-two punch at the end of the summer and forced thousands to leave their homes for safety.

Before those storms hit, Dahl worked on a study modeling the potential impacts of a hypothetical hurricane evacuation on COVID-19 spread. That analysis predicted that type of movement could cause a spike in cases. It also found that social distancing and masks could limit the risk. “The same things that we’d been hearing throughout the pandemic could really help to limit that spread,” she says.

A clear hurricane-related surge in cases never materialized in Louisiana after the hurricanes. There could be a few reasons for that, Dahl says. First, the state offered hotel vouchers to evacuees, which let them escape the storm’s path without crowding into multifamily shelters. COVID-19 cases were also high overall at that time, which makes it more difficult for epidemiologists to figure out where cases were coming from. (High case rates made it hard for researchers to figure out the impact of other potential COVID-19 clusters, like the January riots at the US Capitol.)

The Texas winter storm is a different sort of weather-related disaster than a hurricane, but Dahl says the warnings from the modeling study still apply. “The study that we did was hypothetical hurricane, but it could just have easily had been a wildfire, or an extreme cold snap, or any other sort of event that causes people to start moving around,” she says.

Figuring out if the freezing weather contributes to major COVID-19 spread will be a challenge for the same reasons it was difficult to identify any spikes after the summer’s hurricanes. Cases are dropping around the country, but they’re still high, and it may be hard to see any kind of signal in the data. The storm also isn’t concentrated in one area, so direct impacts on case trends could be hard to see, Dahl says.

Like in Louisiana, though, additional COVID-19 cases aren’t preordained. If people wear masks and officials organize safe places for people to gather and get warm, it won’t be as easy for the virus to spread. “The same lessons apply around the need to keep transmission low, wherever people are going,” Dahl says.