A wearable device can include an eyewear body, onboard electronic components, a thermal coupling and a heat transfer device. The eyewear body can hold one or more optical elements mounted on the eyewear body within a field of view of the user. The onboard electronic components can be carried by the eyewear body at a first portion of the eyewear body and can comprise a heat source that generates heat during electrically powered operation thereof. The thermal coupling can be thermally coupled to the heat transfer device at a second portion of the eyewear body. The elongate heat transfer device can be disposed within the eyewear body and can be thermally coupled to the heat source and the thermal coupling. The heat transfer device can extend lengthwise between the heat source and the thermal coupling to transfer heat from the heat source to the thermal coupling.