I just caught part of a programme demonstrating the safety issues connected with the portable BBQs in foil trays that are so cheap and handy for a camping trip.
One couple had used theirs to cook supper then waited for it to go out, no burning embers, cool to the touch. It was drizzling outside so they took it in their tent and zipped up for the night. In the morning, the gentleman was dizzy and disorientated. His girlfriend had died during the night.
Despite the lack of heat from the embers, the BBQ was still emitting carbon dioxide.
A fireman ran a similar scenario with the embers slightly warm. The carbon dioxide reached danger level within 3 minutes inside the zipped up tent. He said that 6 hours at that level proves fatal.
Please, enjoy the food but then, whatever the weather, leave the thing outside. This goes for camper vans and any other enclosed area.