Staff at the Environment Agency's headquarters are encouraged to wear thermal underwear in the office during winter, it has emerged.
The underwear drive aims to cut heating costs during the winter
The move is part of a drive to reduce heating costs at the London office of the pollution watchdog, according to its chief executive Baroness Young.
Lady Young said everyone could help to reduce their impact on the planet.
The Labour peer was speaking before the launch of World Environment Day, which aims to raise awareness of pollution.
Lady Young wants the public to make minor changes to their lifestyles, such as using energy saving light bulbs, composting waste and taking a train instead of a plane.
She also suggested people turn off the taps while brushing their teeth and take part in car sharing.
And she attacked the growing trend towards air-conditioned workplaces.
"I think it (air conditioning) is becoming a fetish. I hate going to America
where you have got to put clothes on to go into the buildings, rather than take
"And to be frank if we got the Americans to turn down their air conditioning
by four degrees, we would probably reduce the reliance on Middle Eastern oil
that's caused quite a lot of the problems that we are facing on global security
Lady Young said the winter underwear drive meant workers were not "wrecking the planet".
It was an example of how a big difference could be made through "small unheroic actions".
"It's easy in the face of global degradation to just panic...
"I once heard one of our ambassadors saying 'if we are all travelling on the
Titanic why don't we just travel first class?'.
"I don't aspire to that view, I think there are things we can do and World
Environment Day is the opportunity to gang together and by a few small actions
make an enormous difference to the world," she said.
Lady Young said the Environment Agency now drew all its energy from renewable
The World Environment Day campaign is being spearheaded by the Environment Agency and UN Environment Programme.
The UN Environment Programme (UNEP) has also produced an atlas, "One Planet Many People", which compares satellite images of recent decades with contemporary ones, revealing changes to the planet.