So a friend works in a busy kitchen preparing nearly 500 home cooked lunches and has gone into work today to find a lock on the only window in the kitchen. Surely in this heat this is totally un acceptable. Yes there are extractor fans above ovens but they only take a bit of the added heat out from the hobs they don't circulate cool air around. Can't find any maximum working temp laws so what can be done?? Manager is avoiding them as she obviously knows they have done something stupid.