Heat can significantly affect people with spinal cord injuries (SCI), including any residual spinal cord damage from spinal cord tumour compression. If you feel you get sluggish, “funny” legs it is actually a well-known phenomenon, known as Uhthoff’s Phenomenon.
1. Nerve Signal Disruption from Heat
What it is: A temporary worsening of neurological symptoms when your body temperature rises, even slightly.
Why it matters: Damaged nerves (like those after an SCI) conduct signals less efficiently. Heat slows these signals down even more, leading to weakness, heaviness, or strange sensations in your legs.
It’s similar to what people with multiple sclerosis (MS) experience—many describe the exact feeling you are: legs going “funny,” sluggish, or “giving out.”
2. Autonomic Nervous System Dysfunction
After an SCI, the part of your nervous system that regulates temperature, heart rate, and blood flow can be impaired—especially if the injury is above T6. This can make it harder for your body to cool itself, causing you to overheat faster, which in turn worsens the nerve signal issues.
3. Increased Spasticity or Muscle Stiffness
Heat can either relax or worsen spasticity depending on your body’s response. For some, heat makes muscles feel jelly-like and hard to control; for others, it increases tightness and stiffness.
4. Fatigue Amplification
As we discussed earlier, your body is already working harder post-SCI. Add heat stress to the mix, and you get a drop in performance—especially in the legs, which often bear the brunt of walking or standing.
What Can Help
- Stay cool: wear light clothing, use cooling towels or fans, and drink water regularly.
- Avoid prolonged heat exposure or sunbathing.
- Try cooling aids (vests, wraps) if you’re out and about.
- Keep an eye on indoor temps too—many people find symptoms worsen even slightly above room temperature.
If heat is making your legs feel heavy, weak, or sluggish—not stiff or twitchy—then it’s more likely affecting your nerve conduction and muscle tone rather than increasing spasticity.
That classic “melting legs” feeling is strongly linked to slowed nerve signals, particularly in damaged or demyelinated nerves. This is very common with incomplete spinal cord injuries, and unfortunately, it often mimics the original symptoms of the injury, even years later.
While you can’t completely stop this heat sensitivity, you can manage it quite effectively with some practical strategies:
1. Actively Manage Your Body Temperature
- Cooling gear:
- Cooling vests or wraps: Great for pre-emptive use before going outside or during activity.
- Neck coolers and wrist wraps: These help cool your blood where it circulates closest to the skin.
- Cold drinks and snacks: Ice water, frozen fruit, or electrolyte slushies during the day.
- Cooling foot baths: Soaking your feet in cool water can reduce your overall body temperature without shocking your system.
2. Modify Your Environment
- Fans and airflow: Keep air circulating, especially near your legs.
- Portable AC units: Even just for one room or a sleeping area, they can make a huge difference.
- Blackout blinds: Reduce radiant heat in your living space.
3. Pacing & Scheduling
- Avoid peak heat hours (11 am–3 pm) for activity.
- Do mobility work or exercise early in the day, when your nervous system is fresher and temps are lower.
- Break up tasks: Your nervous system gets overloaded more easily in the heat, so pace physical or mentally demanding tasks.
4. Ask About Medication Support
Some people find that low-dose medications (like amantadine or modafinil) can help with nerve-related fatigue or heat intolerance—but this should be discussed with a neurologist or rehab specialist.
5. Log Symptoms
Keep a heat sensitivity diary: note time, temperature, symptoms, and what helped. It can help identify your personal heat threshold and improve planning.
Long-Term Consideration
If heat sensitivity is getting worse over time, it might be worth getting a review with a neurophysiologist or rehab consultant, just to rule out any progression, re-injury, or autonomic dysfunction changes.
If you feel:
- Sudden leg heaviness or numbness
- Lightheaded or nauseated
- Excessively fatigued even after restinga
go indoors and cool down immediately. Your body might not be telling you it’s overheating until it’s too late, because of disrupted autonomic feedback.
At the same time please enjoy your summer but be mindful of its potential impact on you.