What effect does cold compress and hot compress have after double eyelid operation? Cold compress can make the blood vessels in the operation site contract in cold weather, reduce bleeding and be beneficial to recovery; Hot compress can raise body surface temperature, stretch subcutaneous tissue, relax and expand spasmodic capillaries, accelerate blood flow, promote metabolism, promote blood circulation and remove blood stasis, promote granulation and diminish inflammation, relieve swelling and pain, and soften scar tissue.