Removable caulk?

[ciphergoth]

The front room has sash windows and is currently freezing. I'd like to do something cheap to stop the cold air getting in during the winter. I have two ideas in mind

- I'd like to use that plastic disposable double glazing film you can get - any recommendations?

- I'd like to use removable caulk to seal up the windows until the summer, but I can't find any to buy in the UK - eg I can't find anyone selling DAP Seal'n'Peel here. Any ideas?

Comments

[sfred]

In addition to the things you've already thought of (with which I can't be any help) - I find that having thick curtains and closing them as soon as it gets dark makes a big difference.