Hand baggage rules to the UK have been changed today after the threat level in the UK was reduced. For all students now traveling to the UK or from the UK you can now have:
Each passenger is permitted to carry ONE item of cabin baggage through the airport security search point. The dimensions of this item must not exceed: a maximum length of 45 cm, width of 35 cm and depth of 16 cm (17.7″×13.7″×6.2″ approx) (including wheels, handles, side pockets etc.). Other bags, such as handbags, may be carried within the single item of cabin baggage. All items carried by passengers will be x-ray screened.
No liquids of any type are permitted through the airport security search point, other than the following items:
Essential medicines in liquid form sufficient and essential for the flight (e.g. diabetic kit), as long as verified as authentic
Baby milk and liquid baby food (the contents of each bottle or jar must be tasted by the accompanying passenger).
NOTE: The definition of liquids includes gels, pastes, lotions, liquid/solid mixtures and the contents of pressurised containers, e.g. toothpaste, hair gel, drinks, soups, syrups, perfume, deodorant, shaving foam, aerosols, etc.
For more information about this please see the DFT Website in the UK
My recommendation would be to not take any hand luggage for the time being, this will help speed you through security check points and avoid any delays!