Hesson is coaching the New Zealand A side and will miss Otago's next two four-day matches.
He will rejoin the side in late March, midway through its game against Wellington at the Basin Reserve.
Bracewell joined the Otago Cricket Association in August 2007 after teaching at Kavanagh College for 11 years and has been working closely with the Volts this summer.
Part of his job has been to prepare players for first-class cricket, so the opportunity to coach Otago "fits in beautifully" with his role, he said.
Otago plays Wellington in a four-day match at the University Oval beginning on Friday.
The side will be down on class, with Brendon McCullum, Neil Broom and Ian Butler in the New Zealand squad for the first three one-day matches in the five-game series against India.
In-form opener Aaron Redmond has been included in the New Zealand A side and will miss the match, and English all-rounder Dimitri Mascarenhas will join with the England one-day squad.
Offsetting their loss, Indian batsman V.V.S. Laxman will join Otago for its match against Wellington.
"We're not going to be as badly off as I thought we might be," Bracewell said.
Bracewell, who played one first-class game for Otago before pursuing his rugby career, is from a successful sporting family of five boys who all went on to excel at either cricket or rugby, or both.
His younger brother, former Black Caps coach John Bracewell, played 41 tests for New Zealand, and Brendon, the youngest, played six tests.
The caretaker coach expects to name his first side after training tomorrow.
Otago has some ground to make up in the State Championships.
It is in fourth place with four points from four games.
Central Districts leads the competition with 25 points, from Wellington 18 and Auckland 11.
With up to 32 points still on offer, Otago is not out of contention.
But an outright loss to Wellington would leave Otago needing to win its three remaining round-robin matches to make the final.
