This report concerns design aspects with regard to heat transfer. It demonstrates how the selection of hull material effects outer surface temperature hence the infrared contrasts. It also demonstrates how the surface temperature of hull sections in a natural environment can be calculated. Results of numerical calculations using the finite element and finite difference methods are presented. The most important parameters for the calculations have been varied in order to allow a comparison between different hull structures. Outdoor measurements of a solar irradiated hull structure have been performed. The results show that different colours absorb different amounts of heat which results in a variation in the surface temperature.