An article may include an optical transceiver package, which may include a photonics component mounted in the optical transceiver package. The photonics component may generate heat in an operational state. The optical transceiver package may include a sealed thermal chamber that maintains the photonics component between a lower predetermined working temperature and a higher predetermined working temperature. The sealed thermal chamber may include a material that exhibits a first thermal conductivity below a lower predetermined threshold temperature and a second thermal conductivity higher than the first thermal conductivity above an upper predetermined threshold temperature. A method may include retaining the generated heat to raise the photonics component above a lower predetermined working temperature, and conducting the generated heat away from the optical transceiver package to lower the photonics component below an upper predetermined working temperature. A system may include the optical transceiver package mounted to a printed circuit board.