got mine a 'wee little' greenhouse, south facing, and the top just stays on and if its too sunny they get a shading-mesh-thingy (like fabric but with holes in it) over the top. Tomatoes are staying in there all summer tho, they don't like rain from above.
of course if that is what rosa meant with her 'coldframe'--ignore this post
((sorry, don't know what a cold frame is!))
here's hoping your tomatoes and chilis don't become flacid!
(gawd, been waiting to use that word for EVER!!!!!!