The systemic way to treat this is usually to make it work the way Warm + Warm = Burning works:

Make the skill set just 'Bleeding', then have a game script with something like
Code
EVENT CharacterSetBleeding
VARS
	CHARACTER:_Character
	LIST<STATUS>:_RemoveList
	STATUS:_Result
ON 
	FetchCharacterApplyStatusData(_Character, BLEEDING)
ACTIONS
	Set(_Result,BLEEDING)
	ListClear(_RemoveList)
	IF "c1"
		CharacterHasStatus(_Character, WARM)
	THEN	
		ListAdd(_RemoveList,BLEEDING)
		Set(_Result,BLEEDING2)		
	RETURN(_RemoveList,_Result,null)