Miami-Dade County's elections supervisor is telling voters how to salvage mail-in ballot envelopes that arrived already sealed shut.

The problem matters for Palmetto Bay residents, who will choose a mayor and two council members on Nov. 3, and for all Miami-Dade voters with a mail-in ballot in hand. Rain, heat and humidity melted the glue on return envelopes inside mailboxes, elections officials said, according to WPLG Local 10, which first reported the issue Oct. 22.

Miami-Dade Supervisor of Elections Alina Garcia told voters to break the sealed envelope open and reseal it with clear tape before mailing it back. Garcia stressed that the voter's signature is the most important element on the envelope.

If the envelope is too damaged, voters can deliver their ballot in person to any of the county's 28 early voting sites. Garcia said voters must bring identification.

More than 100,000 Miami-Dade residents had already voted by mail as of Oct. 22. Elena Muñoz, a voter featured in the Local 10 report, chose to hand-deliver her ballot rather than mail it.

What local voters need to know

Early voting runs daily from 7 a.m. to 7 p.m. through Sunday, Nov. 1, at all 28 county sites. Any Miami-Dade voter can use any early voting location in the county during that period, according to CBS News Miami. That includes Palmetto Bay and Cutler Bay residents.

The closest sites for south Miami-Dade voters include the South Dade Government Center at 10710 SW 211th St. and the Coral Reef Branch Library at 9211 SW 152nd St., according to the Village of Palmetto Bay's election page. A secure ballot intake station is available at each location during operating hours.

Garcia told CBS News Miami that voters can drop off a mail-in ballot at an early voting site through Nov. 1, but not on Election Day. "On Election Day, you cannot take it to your precinct, but you can always drop it off at our voting headquarters or our satellite office," Garcia said. All mail-in ballots must arrive by 7 p.m. on Nov. 3 to count.

The deadline to request a mail-in ballot was Oct. 22 at 5 p.m.

Palmetto Bay's Nov. 3 general election includes races for mayor, council Seat 1 and council Seat 3. A runoff, if needed, would take place Dec. 1.