While most Brits are being urged to avoid the sun during the heatwave, those required to work outdoors in farm fields are taking extra precautions in the rising temperatures.

The Met Office has issued a heat-health watch alert as temperatures are expected to reach up to 35C later this week, with people being advised to stay indoors during the strongest sunshine.

East Anglia's army of horticultural workers, who need to be outside to pick fruit, vegetables and salad crops, are being advised to cover up, wear sun cream and stay hydrated – and some are being allowed to alter their working hours.

Malcolm Kemp runs a herb business near Thetford, growing baby spinach, coriander, parsley, rosemary and basil, employing up to 65 workers to pick and pack his crops.

He said: 'We are starting two hours earlier in the morning, and the staff are going inside to do the jobs indoors in the hottest part of the day. They will have their normal breaks and then they are finishing early. Also, we are not taking on extra orders.

'They are all supplied with sun cream and hats and told to drink lots of water. If you were going on holiday you would do these things and as long as you are sensible, you are OK. It is just common sense.'