Hypothermia is common in both traumatic injury and other patient populations with major bleeding (e.g., postpartum hemorrhage) and is associated with worse outcomes. Hypothermia causes patient discomfort and hypotension, and increases blood loss. 

• Temperature should be measured within 15 minutes of MHP initiation or hospital arrival and then at a minimum of every 30 minutes (or continuously, where available)
• It is critical to patient survival that the patient is kept warm
  • Every 1°C drop in body temperature increases blood loss by 20%, in part due to impaired coagulation
  • Hypothermia is associated with increased mortality rates
  • Target temperature is ≥36º C

All patients should receive interventions to prevent hypothermia. Warming of patients improves their comfort and, even in the absence of a confirmed survival benefit, it should be a core part of every MHP.

• Ensure removal of wet clothing and minimize exposure by avoiding contact with cold surfaces and keeping a warm environmental temperature
• Warm your patient with warm blankets and air blankets (such as Bair Hugger air blankets) to prevent heat loss
• In addition, use fluid warmers so that the crystalloids and blood are warmed before infusion 

References:

1. Lester ELW, Fox EE, Holcomb JB, et al. The Impact of Hypothermia on Outcomes in Massively Transfused Patients. J Trauma Acute Care Surg. 2019;86(3):458-463.
2. Perlman R, Callum J, Laflamme C, et al. A Recommended Early Goal-Directed Management Guideline for the Prevention of Hypothermia-Related Transfusion, Morbidity, and Mortality in Severely Injured Trauma Patients. Crit Care. 2016;20(1):107.
3. Rajagopalan S, Mascha E, Na J, et al. The Effects of Mild Perioperative Hypothermia on Blood Loss and Transfusion Requirement. Anesthesiology. 2008;108(1):71-77.