Can sweetcorn seedlings survive refrigeration for a couple of days?

Afternoon all,

I know corn love warm temperatures but I am trying to slow down the growth of seedlings I have in time for Friday - I need them to not grow their first proper leaves!

I know temperatures below and around 0 degrees will kill them, but have yet to find something to see if they will survive around 5 degrees approx in the fridge. I could leave them in the polytunnel at our school but just curious of any freak frosts that will KO them! Anyone tried anything similar?

Many thanks :)