This is my last-ditch effort to save you from stupidity

Blood contains cells that are ALIVE. Cells are little sacs of fat and protein and are very DELICATE. Proteins are made of things called amino acids, which form chains. These chains then fold up into 3-dimensional shapes which are then called proteins. At temperatures even a few degrees higher than physiological temperature (which is around 37 to 38 degrees), proteins "denature", which means the amino acid chains unravel from their 3-dimensional structure. Blood cells rupture, and die. 

 

Now, we working in the biological/medical sciences must be very careful in handling proteins and live cells. They are stored in low temperatures. When you want to warm human cells up, they should be warmed up very GRADUALLY, and UNIFORMLY, to 37 degrees and NO HIGHER. 

 

Usually, we do this using a warm water bath, or simply leave it under room temperature. 

 

Now, microwaves are designed to heat food up QUICKLY. The heating also depends water content of the food and the state of the water (is it frozen, etc). So it DOES NOT HEAT THINGS UNIFORMLY. The equipment used for heating up blood for transfusion is VERY CAREFULLY designed in terms of temperature control. The microwave isn't designed for that. It may seem like if you only heat it in the microwave for a short period of time the temperature isn't very high overall, but on a small scale some parts of the blood actually reached a high temperature while other parts have not. The parts that reached a high temperature, the proteins denatured, the cells burst. This PURELY because of the NON-UNIFORMITY in microwave heating. There's simply no way of ensure the liquids are warmed uniformly to your desired temperature in the microwave. It's not designed for that. 

 

Now I can tell you that you are also not supposed to warm up blood on a stove, or on a 暖气片, or leave it out in the scorching sun. This is simply because you can't control the temperature of the blood precisely enough for the blood to be safe to use. Maybe in the future, someone will find out something new in physics that prove microwaves are dangerous, but there's no evidence right now. Currently, the scientific community agrees that conventionally-designed microwave ovens are safe to use. Your terrible example about heating up blood in the microwave (which only appears in a dubious article that can't be verified and written in very UNPROFESSIONAL language, which you can't tell because your English is probably not good enough, actually I don't even know if your English is good enough to fully appreciate what I'm writing right now) CAN'T PROVE ANYTHING. 

 

You understand?