If your semen is cold it may be a sign of an infection or underlying health problem. But it is not normally a sign of infertility. The testicles produce sperm, but they also have two primary jobs: to regulate your temperature and protect the scrotum. To do these jobs, the testicles and scrotum need to be several degrees cooler than body temperature. This is why they are located outside the body in the scrotum (a pouch of skin that contains the testicles and a network of blood vessels).
Semen is made up of minerals, proteins, hormones, and other substances including the sperm itself. Usually, it has a jelly-like consistency. Semen is ejaculated from the seminal vesicles and prostate glands. The sperm only makes up a small percentage of the fluid, however. The rest of the fluid comes from glands such as the prostate to help protect the sperm from the acid environment of the vagina and to supply the sperm with nutrition for the trip. Anything that affects these glands can change the consistency of your semen and may affect sperm quality.
Cold semen can be caused by an injury or a sexually transmitted infection such as gonorrhea or chlamydia. It can also be a sign of a prostate condition such as benign prostatic hyperplasia or acute bacterial prostatitis or a testicular/epididymal disorder such as orchitis or epididymitis. Blood in semen can be a sign of a bleeding disorder such as hemophilia or sickle cell disease and may also be a result of some cancers such as leukemia (blood cancer) or lymphoma (cancer of the white blood cells). It is important to talk to a healthcare professional about why your semen is cold so that you can get it checked out and treated if necessary.