Simple Heated Tool Cupboard.

Keeping tools in a small shed over the winter has its own risks of rust and other damp damage. This simple heater, which can be made with or without a thermostat, will keep tools in fine fettle.

Using two 60 watt bulbs (NOT low energy ones!) mounted in a low corner of the cupboard will give enough heat to keep a 0.5 cubic metre cupboard heated in the coldest winter in the UK. They don't have to be red "fireglow" bulbs but they look good and tend to last a whole winter.
Using two bulbs at least allows one bulb to run between weekly checks if one should blow.

Utilising an old hot water tank thermostat will give ample switching capacity for 120 watts. However these are usually rated at around 40 - 70 degrees Centigrade, whereas we need about 15 degrees Centigrade (about 59 degrees Fahrenheit). If you are lucky there will be a factory setting screw (like the one under the screwdriver in the picture) which can be reset to a suitable range by trial and error. Re-seal the screw with nail varnish.
All outdoor electrical installations MUST comply with the new UK 'Part P' regulations, which means that you may have to have it fitted by, or at least inspected by, a qualified electrician or your local authhority. A shed must have its electrics supplied through an RCD breaker, connected via armoured cable and must be properly earthed.

All my tools are kept snug and dry over the winter in the heated cupboard under the bench. The heater can just be seen (red) in the lower right hand corner, and a sheet of steel protects the tools on the left and the bench on the right from direct radiated heat..
In case any Greens were worried, filament bulbs used this way are 100% efficient.