At least nine people, including two children, have died from heat-related illness so far in 2025 — more than twice as many as this time last year, according to state data.

By the middle of last week, the Maryland Department of Health had already recorded eight total heat-related deaths. Then, on Sunday, a 6-month-old girl died in Harford County after being locked inside a hot car, according to the sheriff’s office.

The string of deaths adds to an already alarming start to the Maryland summer: a child in Montgomery County died in a hot car in May.

“It does worry me. Maryland historically doesn’t have too many of these, which is very fortunate for us,” said Julie Siejack, a registered nurse who works in community health with the University of Maryland Upper Chesapeake Health.

“However, every one of them could be prevented, so that concerns me,” she added. “It’s a hot summer here.”

Just weeks into the official start of summer, Maryland has already equaled the heat-related death toll for the entirety of 2023 and surpassed 2022, when six deaths were attributed to heat.

The start of this summer has also been twice as deadly as the same period last year, state data shows. As of July 3, 2024, Maryland had recorded 4 heat-related deaths.

In total, at least 27 Marylanders died in 2024 from heat-related illnesses. That’s the most in a single year since 2018, when 28 Marylanders died from heat-related illness.

Temperatures crested 100 degrees in Baltimore in late June of last year, though that early summer heat wave was more moderate than the one the region just experienced.

But the death toll climbed over the course of last summer.

In August of 2024, a Department of Public Works employee died after begging a resident on his trash collection route for water. Ronald Silver II’s death came in the wake of scathing inspector general reports on the conditions in DPW facilities and sparked intense scrutiny of the department’s workplace culture.

Heat is the deadliest weather

As of June 25, only one heat-related death in Maryland had been reported. Seven more deaths were recorded by the state as of July 2.

Though the July 2 report covered the week of June 22-28, it’s not possible to say with complete certainty that’s when the deaths occurred, because of the way the state reports and records deaths.

The reports from MDH do show with certainty that the number of people seeking emergency medical attention is up — significantly — year-over-year.

David McCallister, a spokesperson for the Maryland Department of Health, said that just nine weeks into the heat season, which runs from April through early October, Maryland has recorded 729 heat-related emergency department visits — over 60% of the total number of visits for all of 2024.

Heat is the deadliest form of extreme weather, according to the National Weather Service and other experts. Around the world, it kills hundreds of thousands of people annually.

In Baltimore, temperatures have climbed again in recent days, prompting city leaders to issue a Code Red heat advisory heading into Tuesday, when temperatures climbed to 98 degrees.

Mayor Brandon Scott said officials are taking precautions to protect city employees, such as police officers, firefighters, transportation and sanitation workers.

The city plans to keep trash pickup in place during its Code Red advisory, but said Monday night that it would push the start of collection an hour earlier to help workers with the heat.

“This is a time for all of us to take extra precautions — stay hydrated, limit outdoor exposure when possible, and check on others — especially older adults, children, those with preexisting health conditions and pets," said interim City Health Commissioner Mary Beth Haller in a statement Monday night.