The Harvard Fire Protection District responded around 2:47 p.m. to Bunker Hill Road and Island Road in unincorporated Harvard, McHenry County, officials said.
First responders located an elderly man pinned under an overturned tractor in a body of water with only his head visible, fire officials said.
The man was believed to be trapped for nearly three hours before he was found by family members.
Crews were able to free the man within 25 minutes, and he was airlifted to a hospital in Rockford with critical injuries.
The Harvard Fire Protection District was assisted in the rescue by Marengo Fire & Rescue Districts, Woodstock Fire/Rescue District, Boone County District 3, Fontana Fire Department, Mercyhealth MD-1, UW Health Med Flight, McHenry County Sheriff's Office and NERCOM dispatchers.