_1. Place a ligature (tight tourniquet) at once between the site of the bite and the body, but as near the point of entrance of the venom as possible._ _2. Place a piece of ice on the site while preparing a suitable vessel of crushed ice and water._ _3. Place the bitten hand or other member in the iced water well above the point of ligation._ _4. After the envenomed member has been in the iced water for not less than 5 minutes (N.B. research has shown that the danger generally attributed to a ligature is not present when the member is refrigerated), remove the ligature, but keep the member in the iced water for at least 2 hours._ _5. Pack the envenomed member in finely crushed ice. This hypothermia must continue for approximately 24 hours, and the patient must not be permitted to chill, since this increases body stress._ _6. Change from hypothermia to cryotherapy. This is accomplished as follows: after the first 24 hours following the bite, the patient should be kept somewhat uncomfortably warm—that is, to the point of perspiration—and encouraged to drink much water. This step is exceedingly important. Unless the patient is kept uncomfortably warm the proteolytic portion of the venom will not leave the site of the bite. Consequently, when hypothermia is stopped, the concentration of this part of the venom is greater and the tissue destruction will be proportionately increased. Hypothermia should be avoided entirely if this step is not meticulously observed._ [Illustration: _Western black-headed snake_ (Tantilla eiseni). (Courtesy San Diego Natural History Museum)] [Illustration: _Sonora lyre snake_ (Trimorphodon lambda). (Photo by Marvin H. Frost, Sr.)] _7. The warm-up period after Cryotherapy is important. This must be done gradually. Remove the member from the crushed ice and place it in ice water (without ice). Allow the water to warm to room temperature._ Dr. Walter C. Alvarez in the _Santa Fe New Mexican_, 8-18-57: “Recently, Dr. Wm. Deichmann, John E. Dees, M. L. Keplinger, John J. Farrell, and W. E. MacDonald Jr. reported that hydrocortizone is a life-saving drug when given to animals that have suffered poisoning from rattlesnake venom. Instead of only the 17% of the untreated animals that survived, 75% of treated animals were saved.” Back-fanged snakes The southwestern desert regions are credited with harboring several genera of snakes whose grooved back teeth indicate that they may have poisonous properties. Of these, the Sonora lyre snake[11] (_Trimorphodon lambda_) and the Mexican vine snake (_Oxybelis aeneus auratus_) are the only species of sufficient size to be considered as even remotely dangerous to mankind. Species of the genera _Tantilla_ (black-headed snake), _Hypsiglena_, and _Sonora_ are too small and too difficult for the amateur to identify to be considered in this publication.