England boss Eddie Jones has introduced another innovation to bolster hopes of a third straight Six Nations title - heated pants.
England's replacements will wear the NZ$600-a-pair item to ensure they are fully prepared to come off the bench and make the maximum impact.
The pants are a design similar to those used by British Cycling - athletes wore them at the London Olympic Games in 2012 to help their muscles.
But this version, designed by Lizard Heat, cover a larger surface area compared to those seen in 2012. The creators say they are designed to act like a Formula One tire, heating deep into the core of the leg muscles.
According to the product's website, the pants are rechargeable, come with a fully portable power pack and an on/off button combined with a three-level temperature controller button which is integrated into the garment.
There are three heat setting options on the controller - low (38-42 °C), medium (40-45C) and high (45-50C) - as well as a built-in overheating protection mechanism in every product to help ensure total safety.
England are next in action on Saturday against Scotland at Murrayfield and the weather in Edinburgh is forecast to be three degrees when play starts.
It is the latest in a fascinating line of ideas used by Jones to give England every possible advantage under his guidance.
Jones has also had his team scrummaging in training against rival nations Wales and, only last week, Georgia.
He also invited Great Britain's gold medal winning hockey coach Danny Kerry for a meeting, as well as picking the brains of Pep Guardiola, Arsene Wenger, Antonio Conte and Gareth Southgate.
He also planned a visit from Dr Sherylle Calder to help improve players' peripheral vision.
Jones has also used drones in training to provide footage of running lines and had players rehearsing throw-ins wearing boxing gloves with fairy liquid on the ball.