Venom is a complex substance produced by some animals like snakes, spiders, scorpions, bees etc. that is used to hunt prey or defend against predators. The composition of venom varies between species but it generally contains a cocktail of toxins, enzymes, and other proteins.
Venom works by entering the body (through a bite or sting) and disrupting normal bodily functions in some way, usually by targeting the nervous system or blood and tissues. The toxins in venom have evolved to be very effective and potent. This leads to the common question – can heat or fire destroy venom and make it less effective? Let’s take a closer look at venom and how it reacts to heat.
What is venom made of?
Animal venoms contain a mixture of different components:
Proteins
This includes toxins, enzymes, and other proteins. Toxins like neurotoxins attack the nervous system while enzymes break down tissues and cause localized tissue damage. Common venom enzymes include phospholipase A2, hyaluronidase, L-amino oxidases etc.
Peptides
Small protein-like molecules that can have neurotoxic effects.
Amines
Includes serotonin, histamine etc. These cause inflammation and pain.
Inorganic ions
Such as magnesium, sodium, calcium ions. These enhance the spread and potency of venom.
Other organic compounds
Like carbohydrates, lipids, amines etc. Their role is not fully understood.
This complex cocktail of molecules is very potent and disrupts normal bodily functions rapidly. But how does heat application affect venom?
Does heat destroy venom?
Applying heat to a venomous bite/sting is a common first aid measure. But does it really help? Research says no – heat does not destroy or deactivate venom:
Proteins denature but remain toxic
Heating venom to temperatures above 40°C denatures the protein content. The proteins lose their shape and structural integrity. However, denaturation does not destroy the core toxic functions of venom proteins and peptides. Once inside the body, the denatured toxins refold into their active form.
Toxins are resistant
Neurotoxins and small peptide toxins retain toxicity even after boiling. Their potent effects are resistant to brief heat exposure. These molecules have very stable structures.
Enzymes lose some activity
Heating does affect the activity of enzymes like phospholipase A2 and hyaluronidase. But a significant portion of enzymatic activity still remains.
So briefly heating venom to 40-100°C does not eliminate toxicity or make venom harmless. The toxic proteins and peptides retain function.
Why does heat not work against venom?
There are several reasons why applying dry heat or hot water to a venomous sting/bite is not effective:
Brief heat exposure
Typically, first aid heat application uses temperatures of around 40-46°C. At these temperatures, proteins start to denature but venom toxicity is preserved. Temperatures above 80-100°C for longer durations are needed to fully inactivate toxins. Such high heats are dangerous for skin contact.
Venom spreads quickly
Within minutes, venom enters the lymphatic system and bloodstream from the bite site. It gets dispersed around the body where it cannot be affected by localized skin heat.
Stable toxin structure
Neurotoxins and small peptide toxins have very stable molecular structures retained even after boiling temperatures. The rigid disulfide bonds prevent heat denaturation.
Toxins refold
The brief heating from first aid denatures venom proteins. But once inside the body, these toxins readily refold into the properly folded, active conformation.
So brief heat does not permanently destroy venom activity. The components retain potency or refold to regain it.
Does heat improve outcomes at all?
Some limited benefits of heat may be:
Reduces pain
The localized heat can reduce pain at the bite/sting site by relaxing muscles. This provides temporary relief.
Slows venom spread
The heat may partially slow lymphatic transport of venom from the bite location. This may buy some time before symptoms appear.
Placebo effect
The perception that heat fights venom may help manage pain and fear in some cases. This placebo effect can improve outcomes.
However, research has not found any clinical evidence that first aid heat application improves patient recovery or reduces venom toxicity after envenomation. The benefits are minor and short-lived.
Proper first aid for venomous bites/stings
Instead of heat, proper first aid protocols for venomous bites and stings include:
Remain calm and still
This slows spread of venom. Seek medical help as soon as possible.
Wrap tightly above wound
Use a bandage or cloth to wrap the area above the bite tightly. This slows lymphatic transport of venom.
Wash with soap and water
Clean the bite area with mild soap and water. This may remove traces of venom. Avoid chemical disinfectants.
Use cold pack
A cold pack or ice wrapped in cloth can be applied to the wound site to reduce swelling and pain. Cold is safer than heat.
Record appearance of wound
Note down any visible effects like swelling, discoloration etc. This aids proper diagnosis and treatment.
Get antivenom
Antivenom can neutralize specific venoms. But it must match the species involved and be given by a doctor or hospital.
Conclusion
Applying first aid heat to snake bites, stings etc. is not recommended. It does not neutralize or deactivate venom since the toxins retain potency even after boiling temperatures when briefly heated. Proper first aid like washing the wound, constricting bandage, and medical attention with appropriate antivenom are vital for treating venomous bites and stings. While heat may provide short term pain relief, it does not make venom less toxic or improve clinical outcomes of envenomation.
| Venom Component | Effect of Brief Heating |
|---|---|
| Enzymes (phospholipase A2, hyaluronidase etc.) | Some loss of enzymatic activity but still partially active |
| Neurotoxins and small peptides | Fully retain toxicity even after boiling |
| Proteins | Denature and lose structure but refold into active form in body |
This table summarizes how the major components of venom are affected by brief heat exposure like first aid application. While enzymes are partially deactivated, the core toxins retain function and toxicity.