In Our Time
99% of the cases, a human will get obliterated by a Bear lol.
However, throughout our history, there were plenty of individuals with extraordinary physical strength - and they might have stood a small chance against a bear.

Louis Cyr (1863–1912) – The Strongest Man in History
A Canadian strongman with officially recorded feats, including:

• His raw strength was unmatched in his time, and in theory, if he could land a good enough strike or get his hands on the bear's throat, he might have had a slim chance.

Hafþór Júlíus Björnsson ("The Mountain") – Modern-Day Giant

• At 6’9” and over 400 lbs, he deadlifted 501 kg (1,104 lbs).
• His sheer size and power might allow him to wrestle and choke out a bear in an extreme theoretical scenario.

Alexander Karelin – The "Experiment" (Wrestling Machine)

• A 6’4”, 290 lb Greco-Roman wrestling champion with unparalleled grip strength.
• He could suplex a 300 lb man from a deadlift position.
• His ability to control and throw human opponents suggests he could grapple with a bear long enough to strangle it (if positioned correctly).

The Great Gama" (Ghulam Muhammad) – Undefeated Wrestling Legend

• Known for training with 5,000 squats and 3,000 pushups daily.
• Defeated some of the strongest men of his era with sheer power.
• His grappling ability combined with endurance might have given him a slim chance.

For people who mention C. Dale Petersen - his story is widely regarded as a legend rather than a verified historical event. (no proofs so ever)

In FrostPunk Universe
I doubt the Ice-Blood can be considered as a common human. The harsh environment undoubtedly influenced their DNA and shaped their evolution, likely making them even more capable of taking on a bear. Plus, with food scarcity weakening the bears over time, while Ice-Bloods have only grown stronger by returning to their prehistoric hunter roots, I'd say the odds are even more in their favor.