Why would the alcohol thermometer need to be contained in a shelter?
If the thermometer had direct sunlught on it, it would give a false reading because it would be directly heated by the sun’s energy in the rays. The idea of temperature measurement is to measure the temperarure of the immediate medium in which the thermometer is placed. The shelter provides this environment. For accurate internationally acceptable readings the shelter has to conform to specific dimensions and design criteria, as well as a certain height above the ground. Direct sunlight could also cause the thermometer to burst, depending on the maximum temperature scale on the instrument.
