The blood will agglutinate if the antigens in the patient's blood match the antibodies in the test tube. A antibodies attach to A antigens - they match like a lock and key - and thus form a clump of red blood cells. In the same way B antibodies attach to B antigens and Rh antibodies to Rh antigens.
Heat can transfer between two objects touching one another. What type of heat transfer is this? What will the temperature of both objects be after these objects remain in contact for a long period of time?