Hafiji said New Zealand has the highest rates of skin cancer in the world, and Hawke's Bay has the highest rates in the country.
"There is a reason for that – long hours in the hot sun without enough protection," he added.
The Government announced at the end of last month that 2000 RSE workers may be allowed into New Zealand to pick summer crops.
However, it's estimated that Hawke's Bay alone needs even more workers in the horticulture and viticulture sectors - and locals are being sought to fill the gap.
Bostock New Zealand health and safety manager Rhonda Simpson said ensuring employees are safe in the sun is of paramount importance to the company.
"Sunburn, fatigue and heat stroke are risks that we take very seriously and monitor very closely," she said.
"We support our staff as required and ensure that sun safety is covered thoroughly during our inductions."
Hafiji said there must be advice on what new workers should be wearing and mandatory sunscreen application.
"They will be sweating, which means sunscreen will need to be reapplied more frequently than you might otherwise," he said.
"People should be wearing light cotton clothing that covers as much of their bodies as possible – not singlets and shorts."
Simpson said Bostock supplies staff with sunblock and wide-brimmed hats.
"We also ensure that workers stay hydrated and take breaks in the shade as required."
Hafiji said the question of why RSE workers wear plenty of clothing while working in the heat was simple.
"It's probably true that they are used to the heat so it is not so hard on them to fully cover up, but it's also because they know how harsh the sun is from living under it on their home islands and working in it here every summer."