Ninety-five industrial users in north-west England, East Midlands and East Anglia on "interruptible contracts" were earlier told to stop using gas because of high demand from other customers - the first time this has happened in four years.
Roger Salomone, of the Engineering Employers' Federation, said the move had exposed the "longstanding vulnerability in our energy system", showing the nation had to "take security of our energy supply more seriously", including increasing gas storage facilities.
Up to 25,000 homes across Britain have been similarly affected since Wednesday.
Budget airline Easyjet has cancelled more than 100 flights on Thursday, mostly at Gatwick, where a total of 136 inbound and outbound flights were scrapped. British Airways has also cancelled some flights.
Rail services have been severely disrupted by the weather, with train cancellations by several operators.