One appliance and crew from Gerrards Cross, two from Slough and an officer attended.
The first collision was at the junction 2 exit and involved two cars. No-one was trapped or injured.
The second collision was on the southbound carriageway and involved three vehicles. No-one was trapped. A man and a woman were suffering from shock. Firefighters assisted Thames Valley Police, South Central Ambulance Service and Highways England.