In pre-COVID-19 times, the Red Cross would have flown in foreign specialists to help a remote island nation like Tonga recover from a natural disaster.

But after a tsunami and volcanic eruption contaminated Tonga’s water supply last month, the government banned aid workers for fear of COVID-19 coming to a place that had so far escaped community transmission of the virus. (It came anyway.) And because the Red Cross could not easily find a local sanitation specialist, its experts in Fiji had to offer technical support over a patchy telephone line.

"It’s like trying to work under 20 meters of water,” said Katie Greenwood, one of those experts. "You can do it, but it’ll take longer, it’ll be less effective and you’ll want to not do it that way if you can avoid it.”