It's the hottest day of the year at Barnsley Casualty. Sister Vicky has the job of keeping patients and staff cool, but with temperatures outside approaching forty degrees, it won't be easy. Volunteer Jane arrives to dispense drinks ('this could be the day when they need extra hands'). An emergency delivery of ice pops provides temporary relief, but the heat's taking its toll on the hospital generator. Deputy Medical Director Jo rushes from ward to ward, turning off the lights in a desperate attempt to stop it shutting down. Meanwhile Vicky faces staff shortages - and the water cooler's thrown a wobbly. As the hub gets hotter, the emergencies keep coming. Fifty-year-old Michael's brought in after collapsing at home. His family are worried he's had a seizure, but after examining his blood tests, Dr Blanchard has another theory. It's quite a day for hand injuries. Lead cutter Stephen's sliced open three fingers on his circular saw. Emergency Nurse Practitioner Jo administers pain relief and tells him he's lucky - he could have lost his fingers. Meanwhile, refrigeration engineer Mark is admitted after breaking his wrist at work. Waiting to hear if he'll need surgery, he rues his misfortune - he was only four weeks away from retirement. Over in Paediatrics, Abbie's in pain after hurting her hand on a fire extinguisher at school. Dr Klu's trying to treat her, but it's proving tricky - Abbie's afraid of needles.