I’m guessing that when the outside temperature goes below 5 your condition is not yet below 7 so the actions will never run. The only way this would work is if both are true at exactly the same time.
If this is the case then you probably need a template trigger to logically ‘and’ the two conditions (<5 AND <7). If you don’t want to get into templates then the following post expalins another method:
Hope that helps.