Everyone knows that too much sun is bad for them, but it's not just people who need to worry about sunburn. Too much heat is becoming a big problem for South African apple farmers.
"If just 10% of the fruit in your package has sunburn, it automatically becomes a third-grade fruit," says Andre Cloete, Managing Director of Klein Ezeljacht farm, "you can send it to the pack house, but you won't get any money for it."
Typically this fruit ends up being juiced, the least profitable result for a farmer.
Mr Cloete estimates that about a fifth of his traditional red apples have been downgraded this year due to sunburn, while for his green granny apples it's much higher at 60%.
There's nothing wrong with the taste of these apples. In fact, a sunburnt apple typically tastes sweeter because the sun increases the sugar, and gives the fruit a stronger flavour.
The problem is the apples' appearance. In the same way that supermarkets often reject wonky vegetables on aesthetics alone, the apples' unappealing appearance means they are unlikely to sell and are therefore rejected by wholesalers.Image caption Andre Cloete sends the majority of the apples he produces overseas.
To solve the issue, Mr Cloete has invested in extra netting and irrigation, but it's not cheap. He estimates protecting the fruit properly can increase costs by as much as half.
Nonetheless, he believes it's a price worth paying particularly because he expects climate change to exacerbate the issue.
"Sunburn is a big problem and it'll become a bigger problem in future so you have to adapt and you have to choose varieties more suitable to the conditions so you get less sunburn," he says.
He says it's a particular concern for farmers in the Elgin Valley area, which is one of the country's largest apple producing regions.
Like most South African farmers, Mr Cloete sends about half of the apples he produces overseas.
Apples have long been one of the country's top agricultural exports, and fruit from local orchards is exported to over a hundred countries including the United Kingdom, Saudi Arabia and Germany.Image copyright Getty Images Image caption In the Far East, people prefer a bigger, redder apple
Africa's largest apple exporter Tru-Cape currently sends its fruit to 104 countries, but is mainly focused on South East Asian countries such as Malaysia, Singapore and Taiwan, as well as the Middle East.
But meeting the often very exacting requirements of overseas buyers can be tough.
"Most customers buy with their Eyes first," he says.
In Africa, he says that buyers want a "green coloured golden delicious rather than a yellow-coloured one".
In contrast, in China and the Far East they prefer a bigger, red full coloured fruit which crucially has to be blemish free.
The different markets also have different size requirements. "In general, the Chinese market demands larger fruit," he says.Image caption "Most customers buy with their eyes first," says Rolf Pienaar
This of course increases the costs of transporting them, meaning if they're subsequently rejected on arrival it can be an expensive mistake.
"It's a high risk market, if the quality is not right," he says.
Nonetheless, Mr Pienaar says the firm is now exploring "ad hoc opportunities" in the country.
"It can be a very lucrative market if you get the quality and timing right. We are cautiously optimistic about developing trade once export protocols are in place."
This kind of expansion into new markets is crucial for the firm which currently sells around half of its produce to local markets.
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The fall in the price of oil - which has more than halved over the past three years - has made such sales tougher because countries simply have less cash to pay for it, says Mr Pienaar.
But economic factors which are harder to mitigate against are also impacting South African exports.
The weakness South Africa's rand currency against the US dollar has helped the apple industry by making their produce comparative cheaper to many overseas buyers.
But now the rand is strengthening, reversing this advantage.
Mr Pienaar says that as well as putting pressure on the amount of profit farmers are able to make, it also makes it tougher for them to reinvest.
"We need to get used to the uncertainty, it may be the new norm going forward," he says.
It's not just economic factors making it tough for apple farmers. The majority of South Africa's apples are cultivated in the country's Western Cape province, which is currently in the grip of a drought.
Professor Wiehann Steyn, crop production manger at fruit industry body Hortgro says this kind of drought is expected to become more frequent with "serious implications" for fruit farmers.
"Young trees grow less and mature trees carry fewer and smaller fruit. Fruit quality is also reduced," he says.
It's a fear echoed by conservation organisation The World Wildlife Fund, which says climate change could also lead to outbreaks of pests and diseases.
"The increasingly strict non-tariff barriers to exporting apples, including checking the health of export fruits could represent a significant risk to the industry," it warned in a recent report.Image caption Farmers have started to trial newer varieties of apples
Yet, despite the economic and climatic challenges, the South African industry has been performing well over the past few years.
Between 2006 and 2014, production rocketed by a healthy 41% thanks largely to technology developments which helped improve the number of apples produced by a each tree.
Farmers have also started to trial newer varieties of apples which are more suited to changing, and warmer, conditions - an experiment which has helped boost the number of apples produced per tree.
The report concludes that while climate change will add an element of uncertainty, projected increases in local and global demand will mean, "future apple production in South Africa is expected to grow gradually and keep its position as an important export product".
Mr Cloete says he is also optimistic about the future. "You have to farm smarter, and you have to adapt for it… we can definitely overcome the obstacles that we're facing now."