Front line police officers will be issued with woolly hats to help stave off the cold as they spend hours outside in freezing temperatures.
Chief Constable of Thames Valley Police Sara Thornton approved the scheme and the new headwear is now being introduced across the force.
This is the first time that front line officers in Thames Valley have been allowed to wear woolly hats as part of their uniform.
Pc Lisa Stanhope, who is health and safety lead for the force's federation, requested the new head gear because normal hard hats do not keep officers warm.
She said: "Woolly hats have been issued to officers in specialist roles or firearms because they might need to be out in the open all day. But front line officers were never really recognised as requiring that because they are in and out of cars or buildings.
"More and more often front line police officers are used to guard murder scenes or serious incident scenes in really cold and inclement weather.
"I hope that this is going to be something that spreads across the country.
"People are used to seeing TV programmes from America with police in deer stalkers or woollen hats or baseball caps, so I don't think the public reaction will be poor."
Around 6,000 police constables, sergeants and PCSOs are being issued with the "beanie" style hats, which are black with the word "police" or "PCSO" embroidered on them. They cannot be worn while on patrol or in patrol cars.
Ch Supt Andy Standen said: "Thames Valley Police can confirm it has purchased 'Police' and 'PCSO' marked woollen hats to supply to Constables, Sergeants and Police Community Support Officers (PCSOs) working in front line roles, where they have been deployed to static, cold weather incidents such as scene guards or cordons."