Soldier died from being neck-strapped
Neck-strapping was a practice that Vori propaganda claimed their nemesis, the Kradin, engaged in.
People being neck-strapped were staked to the ground at their spread out arms, and a cord was tightly laid running between these stakes and under the neck. The victim was then left to be cooked by the glare. The feet appeared to be left unsecured.
The practice was considered particularly brutal by the Vori due to their cultural belief that the dead could not descend into the Gloried Way After unless their faces were turned down to the earth.
In a brainwashing scenario inflicted on Chakotay, the entire Vori Defense Contingent was found to be neck-strapped, and eventually, Chakotay was neck-strapped himself. (VOY: "Nemesis")