A team of U.S. engineers has developed a wearable patch that could provide personalised cooling and heating at home, work or on the go.

The soft, stretchy patch cools or warms a user’s skin to a comfortable temperature and keeps it there as the ambient temperature changes, said researchers from the University of California-San Diego.

It is powered by a flexible, stretchable battery pack and can be embedded in clothing and wearing it could help save energy on air conditioning and heating.

“This type of device can improve your personal thermal comfort whether you are commuting on a hot day or feeling too cold in your office,” said Renkun Chen, professor of mechanical and aerospace engineering who led the study.

The device, which is at the proof-of-concept stage, could also save energy.