Authorities planning for natural disasters such as hurricanes must prepare for its effect on people struggling with drugs or alcohol, experts tell the Associated Press. The stress of hurricanes leads to an increased danger of relapse and overdose.

Before Hurricane Irma hit Florida, a needle exchange program in Miami distributed extra syringes, while patients at methadone clinics picked up advance medication. Florida, in cooperation with the federal government, allowed methadone clinics to provide up to five days of medication ahead of the hurricane.

Scientists found that during Katrina and Superstorm Sandy, people with a drug problem often avoided evacuating in order to stay close to their dealers. Some shared needles with strangers, which put them at risk of becoming infected with HIV and hepatitis. People who were in treatment missed doses of medication, and used street drugs to avoid withdrawal symptoms.