Three Fall-Outs on a Hot March
During a 12 km march in July the temperature is 41 °C with 30 per cent humidity. Three soldiers fall out within twenty minutes of each other. Soldier A, aged 19, is sweating heavily and complains of headache, dizziness and cramps in both calves; he is fully alert, his temperature is 38.4 °C, his pulse is 112 and his blood pressure is normal. Soldier B, aged 22, was seen to stop sweating about ten minutes before he collapsed; he is now confused and combative, his skin is hot, his temperature is 41.3 °C and his pulse is 132. Soldier C, aged 20, has heat blisters on both heels and a twisted ankle; he is alert and in pain, with a temperature of 37.0 °C. The section carries 60 litres of water, two shade sheets, one stretcher, and a medic who holds intravenous fluids. The nearest vehicle for evacuation is 25 minutes away.
1. Identify the most likely condition affecting each soldier and rank them for evacuation. Justify the ranking.
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Soldier A - heat exhaustion with heat cramps. Heavy sweating, headache, dizziness, cramps and a pulse of 112 point to salt and water loss. He is alert with a near-normal temperature, so this is not immediately life-threatening, but untreated heat exhaustion can progress.
Soldier B - exertional heat stroke. Core temperature 41.3 °C plus confusion and combativeness means the brain is already affected; the earlier cessation of sweating is an ominous sign. This is a life-threatening emergency.
Soldier C - blisters and an ankle sprain. Temperature 37.0 °C, alert, injury limited to the feet. Not a heat illness and not an emergency.
Ranking for evacuation: B first, A second, C last. B's survival depends on how quickly the temperature is brought down, so he takes the stretcher and the vehicle. A must be rested, shaded, cooled and given oral fluids with salt, and then watched - he can be moved by vehicle after B. C is walking wounded and can be helped along or picked up on a later lift; giving him the stretcher would delay B, and delay is what kills in heat stroke.
2. Set out the first 15 minutes of management for Soldier B and justify the order of actions.
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Order of actions - cool first, move second.
- Move him into shade and strip off clothing and equipment; every layer slows heat loss.
- Start active cooling immediately: wet the skin and fan it, and place cold packs or wet cloths at the neck, armpits and groin where large vessels run near the surface. Cold-water immersion is best if a trough or sheet of water is available. Do not wait for the vehicle before starting.
- Airway and position: he is confused and combative, so protect the airway and do not force fluids into his mouth - an uncooperative casualty can aspirate. Oral fluids are for the alert casualty only.
- Medic: intravenous fluids, oxygen if carried, and repeated temperature and pulse checks.
- Evacuate with cooling continuing - fanning and wetting go on during the move.
Justification: in heat stroke the damage is driven by the duration of high core temperature, so the speed of cooling matters more than the speed of departure. Loading a casualty who is still at 41 °C and driving for 25 minutes with no cooling wastes the treatment window. This is why "cool first, transport second" is the rule.
3. Soldier A's temperature is only 38.4 °C. Why can that not be used to rule out serious heat illness, and why should Soldier C not get the stretcher?
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On Soldier A's temperature: a field reading taken at the mouth or armpit is a poor guide - it lags behind core temperature, is cooled by sweat and moving air, and varies with how the probe is placed. Diagnosis in the field rests on the whole picture: work in heat, heavy sweating, cramps, dizziness, a pulse of 112 and a normal blood pressure. A near-normal number does not cancel those signs, and it certainly does not exclude progression to heat stroke if he keeps marching. He is treated as heat exhaustion, rested, cooled, given salted oral fluids and re-checked - not sent back into the ranks because "his temperature is fine".
On Soldier C: he has a normal temperature, is alert and has a foot injury, so he can walk with assistance. Resources are the issue: there is one stretcher and one vehicle lift 25 minutes away. Committing either to a walking casualty delays transport for the soldier whose brain is already affected by heat. Triage is about doing the most good with what is on the ground, so C waits for the next lift.