Instant chemical heat packs are available. These might be the most efficient means of providing extended applications of heat for use on horses. A plastic pouch contains chemicals that produce heat when they are mixed. No additional equipment is needed and the heat lasts for about 90 minutes. This self-contained heat source becomes quite hot at first, so one should quickly put it in the accompanying cloth sleeve.
Sleeves are available to fit various areas of the horse.
By soaking the sleeve before inserting the heat pack, moist heat is provided. Heating lamps can create a fire hazard should they fall into the straw bedding. In the usual situation, hung from a barn rafter over the horse, they do not provide enough penetrating heat to be of much therapeutic benefit. Equine solariums have been built so several lamps fixed to a metal arc can be lowered closer to the horse's back. Horses seem to enjoy standing under them, particularly when the weather is cold and they are sore.