The headlights of a Land Rover and tools were stolen by thieves from vehicles parked in the Hathersage area.
Offenders took the headlights from a Land Rover Discovery parked in Smithy Meadows overnight between Monday, August 5 and Tuesday, August 6.
In a separate incident between the same dates, thieves smashed the window of a van parked in The Crofts and made off with tools stored inside.
PCSO Anthony Boswell, from Hathersage Safer Neighbourhood Team, said: “Thieves will go for vehicles that look like easy targets so it pays to take extra security steps, such as parking in a well-lit area and taking valuables indoors with you.
“We’ve noticed many cars with their windows left down in the hot weather and that can be an open invite to a thief, so we’d urge drivers to take the few seconds to make sure their vehicle is properly secured.
“It’s also important that people report suspicious activity or vehicles to police straight away so that we can take action and potentially stop a crime before it happens.”
The warning comes as police and Derbyshire Dales District Council have teamed up to launch a car crime awareness campaign over the summer months.
Signs have been placed in car parks across the Dales reminding people to secure their vehicles and take valuables with them and officers have been leaving cards with the same message on windscreens of parked cars.
Officers are also appealing for information after coping stones were stolen from a wall in Birley Lane, causing other stones to fall into the road.
That offence took place between Tuesday, August 8 and Tuesday, August 13.
Do you have information relating to any of these crimes? If so, call Derbyshire police on 101 or Crimestoppers, anonymously, on 0800 555 111.