Amazon said Saturday it will raise overtime pay for workers in its US warehouses between March 15th and May 9th, Reuters reports. Instead of the standard time-and-a-half they receive now for overtime, Amazon warehouse workers in the US will receive double their hourly rate for every overtime hour worked in a given workweek, the company said.

The announcement comes a day after four US senators sent a letter to Amazon CEO Jeff Bezos asking him to respond to questions about how the company is keeping its warehouse workers safe during the coronavirus outbreak. The senators sent the letter two days after the first US-based Amazon warehouse worker tested positive for COVID-19, the disease caused by the virus.

Amazon warehouse workers have said that the uptick in orders— as people hunker down at home to prevent the spread of coronavirus— has caused many to become concerned for their health. The Verge spoke with 24 warehouse workers and delivery drivers, who described crowded workplaces, a lack of screenings for symptoms, a shortage of cleaning supplies, and a pace that made sanitation difficult.