Are You Accidentally Inducing Hypothermia?

Any kid who has ever drank a Slurpee too fast on a warm day, and found themselves shivering and chilled, knows that cold fluids can be remarkably effective at cooling the human body. I had this lesson reinforced while I was working as a consultant for a bio-tech company. The company was looking for methods to induce and maintain therapeutic hypothermia.

I can disclose much about the different methods and results that the engineering team experimented with, but I will tell you this, if you want to drop someones core temperature fast, nothing is quite as effective as a quick, two litter bolus of  cold saline. This is why most therapeutic hypothermia protocols begin by inducing hypothermia, not with some fancy cooling blanket or external cooling device, but an infusion of 37 degree saline.

With that thought in mind, how important should it be to keep the saline we infuse into our patients whom we want to keep warm at something close to body temperature? I hadn’t really given the question much thought until I got an email from Scott.

Scott’s one of those SWAT medic types. He works with his local SWAT team to provide on site medical interventions if the need arises. Scott had an interesting experience with an accidental infusion of ice cold saline. I’ll let Scott take it from here:

“I am on a tactical medic team.  The temperatures here have dropped recently (as they always do this time of year). We recently had a call out. Most all of our medics have an entry bag that stays in their vehicle and a main bag that stays in the response vehicle. As you can imagine, neither of these are heated or cooled, “temperature controlled” environments.”

“On this call out, we had an officer who was walking through the neighbors yard to provide perimeter security when he obtained a fairly significant laceration on his lateral right leg. As most officers would, he brushed it off, vowing to deal with it after the incident. After about 45 mins he finally called for a medic. We replaced him with another officer and escorted him back to the command post. “

“The officers leg from the laceration down was soaked with blood, pant leg, sock, everything. This officer was being particularly hard headed and said he would go get it looked at in the morning and asked us to simply bandage it for him. My partner was able to talk him into an IV because of the blood loss. I was focused on bandaging his leg while my partner started a 500 cc normal saline bag. I left to go back to the perimeter after finishing with the bandage and my partner stayed back to monitor him and finish his IV. “


“I was at the perimeter for all of 20 minutes when I was called back to the command post for assistance. When I got back the officer was lethargic, his extremities were cold to the touch his teeth were chattering, and he was slightly confused. “

“My first thought after, “Oh shit!” was shock, but I had a brief moment of sanity before the panic set in. I took my partners glove off and told him to grab the IV bag. As you guessed it was freezing cold to the touch. He had put the officer into hypothermia by giving him a sub-zero fluid bolus. “

“We quickly called for a unit, covered him up, took vitals and proceeded through our hypothermia protocols. “

“It had not even occurred to my partner that his IV equipment has been in his freezing cold trunk all night, and even when the patient went down hill, he didn’t see the obvious signs of hypothermia. In treating this officers laceration he nearly caused a more serious medical emergency. “

“Most agencies keep their trucks in a climate controlled bay or have a solution to heat their units or bags. However there are some that don’t. I thought this might be worth sharing with you. “

Thanks for the story Scott. And yes, it is worth sharing. I’ve mentioned before the importance of keeping trauma patients warm. As winter sets in here in Colorado, I can imagine all kinds of scenarios where this mistake could play a significant role in the patients outcome. Our medic units use warming plates for our IV bags, but the one in the kit remains unheated.

I also consider how many times I’ve started IV’s on the side of the road in a snow back or deep in the back-country. IV bags get left outside on special events and coverage situations like the one Scott describes here all the time. The next time you’re outside in the cold or pulling an IV bag out of a kit, don’t forget to feel that solution. Induced hypothermia does have its applications, but most of our patients will benifit from warm fluid.

Thanks for the tip Scott.


  1. Great Article Steve, Glad I could share this experience with everyone. Keep up the great work.

  2. Sean Fontaine says:

    I love my saline warmer and realize the value of not creating hyopthermic pts every time we start a line now. Compared w/ten years ago when saline warmer meant throwing 4L of fluid across the heater vents on the dashboard during winter time and in summer leaving them in the back cabinets since the A/C was so poor any ways.

  3. We use a baby wipe warmer to keep our 1000mL bag warm, it works great and it is very cheap a plus for us volunteer departments with a low budget.


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