Most cold injury in St. Louis does not happen at the temperatures people expect. It happens between roughly 30 and 50 degrees, in the wet, over hours rather than minutes.
The temperature that actually hurts people
Hypothermia is widely assumed to be a deep-winter problem. In people living outside it is not. Research on cold exposure in this population repeatedly finds injury and death clustering in damp, windy conditions well above freezing, because wet clothing and wind strip heat far faster than still dry air at a lower reading.
That matters practically. A night forecast at 40 degrees with rain is more dangerous than a dry night at 25, and it is the night nobody opens a warming centre for.
What to watch for, in order
- Shivering that stops. Shivering is the body working. When it stops and the person is still cold, that is not improvement — it is the body losing the capacity to rewarm itself, and it is the point at which help is needed.
- Confusion, slurred speech, stumbling. These are frequently read as intoxication and treated as a behavioural problem. In the cold they are the commonest presentation of moderate hypothermia, and the mistake costs lives.
- Unusual calm, or undressing. Paradoxical undressing is real and it is a late sign. Someone removing layers in the cold needs emergency help immediately.
Feet, which are the injury nobody counts
Nonfreezing cold injury — trench foot — needs no ice at all. Prolonged wet and cold above freezing is sufficient, and boots that never dry are the mechanism. It is painful, it disables walking, and in a person who has to walk to eat, that is a cascade rather than an inconvenience.
Dry socks are a genuinely medical intervention here, which is why they appear on every in-kind list we publish. Foot care when you are outside covers what actually helps.
What helps, concretely
- Dry beats warm. A dry mid-layer under a damp coat does more than another damp layer on top.
- Cover the head and hands before adding torso layers.
- Get off the ground. Cardboard, a pallet, anything. Conduction into cold ground removes more heat than the air does.
- Alcohol feels warming and is not. It moves blood to the skin, which increases heat loss while removing the sensation that would tell you.
- Eat something. Rewarming is metabolically expensive and it fails without fuel.
What we do about it
The street medicine team goes out in exactly the conditions described above, because that is when it matters and when the fewest other services are running. Nothing is asked of anybody first. Street medicine outreach explains how contact works, and emergency and crisis resources lists what to do when it cannot wait for us.
Sources
- Zhang P et al. Cold Weather Conditions and Risk of Hypothermia Among People Experiencing Homelessness: Implications for Prevention Strategies. International journal of environmental research and public health, 2019. PubMed 31491874
- Akhanemhe R et al. Health impacts of cold exposure among people experiencing homelessness: A narrative systematic review on risks and risk-reduction approaches. Public health, 2025. PubMed 39879914
- Rathjen NA et al. Hypothermia and Cold Weather Injuries. American family physician, 2019. PubMed 31790182
- Zafren K. Nonfreezing Cold Injury (Trench Foot). International journal of environmental research and public health, 2021. PubMed 34639782