Post A-Level Natural Sciences application

Hi, so I've just finished year 13, and am thinking of applying (post A-Levels) for Natural Sciences at Cambridge prompted by getting 4A*s in Maths, Further Maths, Chemistry, and Physics with an average ums of 96. My problem is that I will be applying during a gap year. I haven't got anything planned for it yet (it was a rather impulsive decision), but I've heard from various places that unis and Cambridge in particular don't like gap years for science applicants in case they go rusty. I am fully prepared to keep up all of my subjects, revising, making sure I don't lose anything, but is this enough? Will Cambridge want me to find a work placement, which is going to be hard to find at this short notice, and if I'm honest will probably be a lot less beneficial than reading around the subject. I've done work experience at research places before and it largely consists of making tea, and doing grunt work, but it can undoubtedly be made to sound quite impressive in your personal statement.

So how big an issue is a gap year for NatSci at Cambridge? What is the best thing I can do during it to make my application as strong as possible?

Thanks everyone