What about heat transfer from (coil to hose) if coil is near exhaust?

Unicoils will remain at the same temperature as the hose. Any excessive heat for example if a Unicoil approved hose was incorrectly fitted and a Unicoil was left touching even a very hot surface such as the exhaust manifold the heat would conduct and spread across the Unicoil and what little heat left that did not convect into atmosphere would be absorbed by the hose wall and into the cooling system. Unicoil approved heater hoses have a high temperature rating of +125 degrees Celsius, well above the average heater hoses on the market that normally have a rating of +100 degrees Celsius. Extensive field trials have shown no heat damage or irregular wear have ever been caused by a Unicoil. If anything a Unicoil aids in cooling due to the increased surface area provided by the coil allowing increased air convection cooling.