Slaves who dared to speak up to/against their master suffered the punishment of the Iron Mask. During the harvest of sugarcane, the iron masks were used to prevent them from tasting or eating the cane when they were thirsty or hungry. 
Neck collars were also placed on them for months to remind them of their wrongdoing if they did any 'wrong'. Collars were thick and heavy and often had protruding spikes that made fieldwork difficult and prevented the wearer from resting at night.
