This has happened to me now on several occasions. This issue has also occurred with a MedKit.

Also note, this is occurring on Experimental: 0.45.12499

Update This issue does not appear to reproduce in the current experimental version 0.37.115791.**

I'm also exhibiting the exact same thing. I'm noticing it to come and go. If standing in one place I don't drop my FPS. When running it will stutter from 62+ FPS to as low as 7FPS every few seconds.

This issue did not affect me using my old hardware:
: VGA 131-GT-E767-TR LGA 1366 Intel X58 SLI 3
: Intel I7 950 Bloomfield @ 3.06GHz
: EVGA 01G-P3-1556-KR GeForce GTX 550 Ti (Fermi) FPB 1GB 192-bit GDDR5. Driver334.89
: 16GB DDR3 @ 1600
: 850W Power Supply

Issue started after my upgrade to:
: MotherBoard: Asus Maximus VI Gene
: Intel I5-4670K @ 3.40GHz
: 16GB DDR3 @1600 (Same as old)
: NVIDIA 760 GTX 2GB DDR5 Overclock. Driver: Nvidia driver 334.89
: Windows 8 64bit (Same as old)
: PNY SSD 240 GB
: 850W Power Supply (Same as old)

: No hardware has been overclocked.
: All graphic settings have been reduced to low or off.
: CPU's Cores have been unlocked
: Steam Launch Options for DayZ:
-maxMem=16384 -maxVram=2048 -nosplash -noPause -cpuCount=4, -exThreads=3

This has happened to me now on several occasions. This issue has also occurred with Yellow Protector Cases.

Also note, this is occurring on Experimental: 0.45.12499

I am no longer able to reproduce this bug.