Final answer:
Re-warm a vasoconstricted patient, it is necessary to promote vasodilation in order to increase blood flow to the skin and facilitate heat radiation into the environment. This can be done by applying external warmth or administering vasodilator medications.
Step-by-step explanation:
When re-warming a patient who is relatively vasoconstricted, it is essential to induce vasodilation to increase blood flow to the periphery and promote heat transfer. Vasoconstriction conserves heat by directing blood flow away from the skin and extremities to keep the core organs warm. In contrast, vasodilation allows more blood to flow from the warm body core to the surface of the skin, facilitating heat radiation into the environment.
Options such as increasing the amount of muscle contraction or sitting on a warm rock help to promote heat generation or provide an external heat source, respectively. However, they do not directly cause vasodilation. Consuming more food to increase fat serves as insulation and is not a strategy for acute re-warming. Thus, to increase the amount of vasodilation, one could use methods such as applying external warmth, administering vasodilator medications, or using techniques like warmed intravenous fluids, if appropriate for the clinical scenario.