The priests wore robes. However, when they worked at the brasen altar, they had to step up on a higher shelf above the people. The Lord was concerned that they not show their nakedness. Exodus 28:42 gave these instructions for this occasion, "And thou shalt make them linen breeches to cover their nakedness; from the loins even unto the thighs they shall reach." There is nothing anywhere in scripture to indicate that God has changed His opinion on nakedness or His definition of it. Styles of clothing may come and go, but this will stand in the eyes of God; even if it does not in the eyes of man. Most of the shorts I have seen show the thighs and God would evidently consider this a display of nakedness.
Another thing to consider is that comfort should never be the judge of what is right or wrong. I have heard this argument concerning clothing over and over again--as if God is so concerned about our comfort that He will not mind us going against His stated precepts if obeying them will make us uncomfortable. I do not mean to seem harsh, but God is not there for our comfort. However, let me suggest that the comfort issue is not as real as you imagine.
Have you ever considered what the Arabs wear in desert climates. They cover their bodies from head to toe. Perhaps they are extremely uncomfortable, but perhaps they are not. When we get hot, we sweat. Lack of clothing allows the sweat to quickly evaporate and that may create a cool feeling. However, when the body is covered, the sweat is trapped and the liquid tends to cool the body as well. I really believe that the devil lies to us about the heat issue and convinces us that we cannot make it unless we remove our clothes. For most of human history, people kept their clothes on in the heat, but now we cannot stand it. Something does not add up.
In the past, I worked in hot warehouses with no air conditioning where the temperature easily made 100 degrees even with some fans blowing and Tennessee is almost always humid. I always wore a shirt and t-shirt and long pants. Sure, I was hot, but it really was not that bad. It is all a matter of what we get used to.
