Shandu Slaughter, 28, and Kristin Wills, 21, both of 839 N. Franklin St., were taken into custody after an autopsy report showed their child Marcus Isaiah Wills died from dehydration.
They're now charged with involuntary manslaughter.
The child died on March 20. In a statement, police said Slaughter put the child down for a nap at 2 p.m., and the couple left him unattended in a heated room in which the temperature climbed into the 90s.
When Wills checked on the toddler around 9 p.m., she found him unresponsive.
Both Slaughter and Wills are being held in the Wake County jail under $1 million bond.