Sorry to raise this as am sure it must have been raised before but can't find it - does the Survival bag requirement for summer mean only the thick plastic "sleeping bag" types, or would a space blanket be considered ok?
Thanks

Catherine, in the final details for this event the rules actually state survival bag or foil blanket.

Have the best of both worlds with a survival bag made out of foil. Costs a bit more, also slightly heavier/bulkier than a foil sheet, but surely much more effective.

Thanks Graham...