Canon Speedlite 430EX III-RT - Manual (Page 93)

93
f Flash Firing Restriction due to Temperature Increase
Even when Level 1 warning is not displayed, the firing interval will be
extended as the flash head begins to heat up.
If Level 2 warning is displayed, allow a rest time for at least 30 min.
For cautions on the number of flash firings, see page 15 (continuous
flashes) or page 36 (modeling flash).
When Level 2 warning is displayed and remote release (p.66), test flash
or modeling flash (p.65) is performed by a slave, the firing interval
becomes approx. 40 sec.
Do not touch the flash head, batteries, or the area near the battery
compartment immediately after firing continuous flash or modeling flash.
Touching them may result in a burn. Before replacing the batteries, make
sure that they are cooled.
When C.Fn-22-1 is set (p.85), the warning with red illumination of the
LCD panel will not be displayed even if the temperature of the flash head
rises.