Use this trace heating kit from RS PRO to insulate your cables from temperature fluctuations. The heating tape in this kit installs onto the cable to self regulate the temperature, which stops frost from developing in the cold and keeps excessive heat from warping its material.
The tape is 30 metres long so you can fully insulate the length of the trace heating cable. The end seals attach to the front and back of the cable to keep the connection extra secure from cold seeping through gaps. Polyolefin sheath material keeps the cable resistant to abrasion, mildew and chemical contamination.
The kit also comes with fixing tape to fasten the heating tape tightly to the cable so the fittings won't come loose. Three warning labels will stick to the pipe to make workers aware of the live electrical current inside.