There are almost no adjustable electronic trip elements which are sensitive to ambient temperatures.
There are almost no thermal magnetic breakers with 'dial adjustable' long time (nominal amp rating) elements. The majority of thermal magnetic molded case breaker adjustments are for the magnetic (instantaneous)portion of their trip curve.
The best answer probably depends on the actual installed breaker.
Old dusty dirty thermal magnetic breakers in poorly ventilated locations/equipment are likely to be affected by high ambient. for about the past 50 years, the target ambient temperature for molded case breakers is 40°C (104°F). Breaker manufacturers usually offer information on determining the breaker's performance in non-standard ambients.
