Sepsis and low temp

I believe low temp has something to do with diffuse organ and skin under-perfusion due to massive cytokine release, which is a result of bacterial (or fungal) toxic waste product.

Septic patient would also have low BP, have high lactate levels (4 or higher), respiratory alkalosis and hyperglycemia.

In a septic patient, the body's natural response to any foreign invader (bacteria, fungi, etc) is to massively vasodilate in order to dilute and spread out the invader in order to more easily destroy it (think how tough a roman phalanx is and how much easier it is to attack and destroy it when it is not bunched up in the testudo formation). However the massive vasodilation also leads to hypotension and as a corollary, hypoperfusion.

With the vasculature dilated and subsequent increased surface area, heat in the vessels is much more easily lost. The body can also tell that there is hypoperfusion and will shunt blood away from the non essential periphery and into the vital organs. With the hypotension and hypoperfusion the kidneys are usually the first to take the hit and the CVVH needed can drop the temperature as well, especially if the warmer is not on. The massive amounts of fluid that was probably initially dumped into the patient with the onset of hypotension is also not helping with the temperature issue as well.