Civil servants sweltering through the summer in formal suits have been told they can shed their jackets and ties when temperatures hit 30 degrees Celsius. The decree - issued after a meeting of top officials - has reached Financial Secretary Donald Tsang Yam-kuen, who has told his closest aides his bow-tie will go when the heat is on. It brings 186,000 public servants into line with their counterparts in Singapore and Thailand, where open-necked shirts are the order of the day when temperatures rise. The dressing-down order was delivered by Deputy Secretary for Civil Service Duncan Pescod in a letter to the civil service staff newsletter published yesterday. 'It is about time we abandoned some of the conventions of the past and recognise that it is simply illogical for us to wear jackets and ties when the temperature outside is in excess of 30 degrees Celsius. I hereby call on all colleagues to cast off the yoke of unsuitable attire and 'relax',' Mr Pescod said. Last year the temperature exceeded 30 degrees on 112 days. But Mr Pescod made it clear he did not want staff to get carried away. 'Of course, we are not suggesting shorts or T-shirts would be acceptable attire except perhaps on designated dress-down days,' he wrote. Public servants will have to don a suit and tie when attending Exco or Legco or when they meet the public. Mr Pescod said the move would cut cleaning bills and slash the civil service electricity bill by allowing air conditioning to be turned down. Allan Roger, president of the Association of Expatriate Civil Servants, quipped: 'It's typical of Hong Kong's bureaucracy that instead of just saying you can dress more casually, they come up with a specific 30-degree rule.'