Create a super efficient stove out of tin cans and some insulation.
4 tin cans - ideally not the same type so one can just about nest in the other (when jammed in - see photo)
One catering sized tin can (not shown in the photo)
Make a chimney by cutting the bottom and top off one can, stuff the two together.
Mark up a circle on the side of the chimney that should be just big enough for a tin to slide in.
Cut out that circle, and stuff one tin can (with both top & bottom cut off) into that hole.
Mark out another circle on the catering sized tin, and cut it out.
Cut out flaps from the top of the chimney - like at the top of a castle - so that air and flames can escape at the top.
Put the chimney in the catering can, and slide the horizontal can through the catering can, into the chimney.
Fill the space up between the chimney and catering can with earth, sand, or other insulating materials (wouldn't recommend stones incase they explode).
Fold a lid up so if can rest horizontally half way up the horizontal can, like a shelf, which is used to rest the sticks on. This allows cool air to be drawn in under the sticks.
Make a tiny fire in the bottom of the chimney, and push in some sticks horizontally - they then just need to be pushed in every so often as they burn. Saucepan on top, and you have a hugely efficient stove.