The TUC has urged British employers to follow the example of the Japanese by relaxing workplace dress codes in order to help workers cope with the hot weather.
Last year, Japanese prime minister Junichiro Koizumi urged workers to leave their jackets and ties behind in order to save energy by reducing air conditioning use.
Providing a more cool and comfortable work environment for staff will not only save energy bills, but will help employers to get more out of staff, the TUC claims.
Although more relaxed clothing may not be suitable for those working with the public, the union has asked employers not to use bogus health and safety concerns as a reason to banish shorts back to the beach.
"It's no fun working in a baking office or factory and employers should do all they can to take the temperature down," said TUC secretary general, Brendan Barber.
"Clearly vest tops and shorts are not suitable attire for all front line staff, but those not dealing with the public should be able to discard their tights, ties and suits."
Among other measures suggested to employers for combating the heat wave were moving desks away from windows, providing a regular supply of cool drinks and introducing flexitime so staff can avoid commuting at rush hour.