In this paper we present the experimental results of an investigation aiming to demonstrate the role of constraints like substrate temperature and environmental pressure on the evaporation process of wetting droplets. It is clearly shown that increasing the temperature or reducing the pressure enhances the evaporation rate. The effect of changing these two parameters on the wetting behaviour is however not similar. The wetting behaviour is dictated by the surface tensions between the three phases (liquid, vapour and solid). Whilst pressure has little effect on these interfacial tensions, the temperature can greatly change these latter. A force balance at the triple line dictates the anchoring of the three‐phase line; changing any of the interfacial tensions can alter this force balance. Increasing temperature tends to reduce the liquid‐vapour surface tension, which reduces the Young unbalanced force acting on the triple line. These results in promoting the anchoring of this latter. Reducing pressure will enhance evaporation, which will lead to a greater evaporative cooling effect, this will increase the force acting to depin the triple line. The relationship between the evaporation rate and the anchoring of the three‐phase line is discussed. The evaporation rate is found to be constant and proportional to the droplet base as far as the three‐phase line is anchored. After depining of the triple line the evaporation rate is reduced. This can have important implications in various applications where both the evaporation and wetting are to be controlled. © 2004 American Institute of Physics