A portable moist heat delivery system comprising a water vapor generating portion comprising a water vapor source and a heat source; a water vapor-air regulating portion, said water vapor-air regulating portion comprising a water vapor-air mixing layer, and a water vapor-air distribution layer; said water vapor generating portion and said water vapor-air regulating portion being in fluid communication; and said water vapor-air regulating portion having a latent heat delivery surface disposed adjacent said water vapor-air regulating portion which delivers moist heat at a preselected temperature range wherein about 15% to about 95% of the moist heat is latent heat of condensation. Methods include delivering improved pain relief, blood flow, relaxation, and reduced cardiac workload.