Heat is for mild to moderate pain. It helps expand blood vessels, increases blood flow to the area, and provides relaxation for the tissues. You can get heat therapy from heating pads, rice socks, warm water, etc. This is also beneficial for labor.
Cold is used for more severe pain, and penetrates more deeply than heat. It can reduce the blood flow to the area and help reduce swelling. Cool to cold compresses can be used as can special cold packs. These are used many times in labor for back pain, and for cooling down a mom who is working hard.
No matter which therapy you use, remember that alternating between the two will ensure the best results for most people. You will also want to watch the temperature of the products. Never place heat or cold packs on numbed skin.
Relaxation and tension are often relieved by pressure and massage. You don't have to be a professional to be able to give a great massage. The most important thing is to listen to your partner about how they want to be massaged and what techniques feel the best to them. A light (usually on the belly) is called effleurage. A firm, solid pressure on the sacrum (low back, just above the bottom) is called counter pressure.
Massage oils and lotions can add to the relaxation effect. The scents that you choose should be pleasing to both people and should be chosen based on the goal of the massage. For example, mint is more invigorating but lavender is more soothing. The lotion or oil can also reduce friction during the massage. Some recommendations might be: grape seed oil, prepackaged lotions, etc.
This Mexican shawl can be used in a variety of ways to help alleviate the pain of labor and increase your ability to relax.