Health warning from First Aid Educator Sarah Jefferies, Emergency First Aid At Work Course
With testosterone replacement therapy (TRT) searches up 2000% and over 153,000 monthly searches across the UK alone, a first aid expert has issued a seasonal health warning: the effects of synthetic testosterone may be more dangerous in hot weather.
Sarah Jefferies, a qualified first aid educator from Emergency First Aid At Work Course , says:
“Testosterone increases your red blood cell count and can thicken the blood, which already puts strain on the heart. Combine that with dehydration, high heat, and intense workouts, and you’ve got a recipe for serious medical incidents.”
While testosterone therapy is often marketed as a way to boost energy, libido, and mood, Jefferies says many users, particularly men self-prescribing via online retailers — are unaware of the added cardiovascular stress during hot weather.
“Summer heat already causes blood vessels to dilate, increases sweating, and reduces your blood pressure. If you’re also on TRT, especially without medical supervision, you’re far more likely to suffer heat exhaustion, blood clots or even cardiac symptoms.”
Warning signs to watch for:
- Rapid heart rate, even at rest
- Headaches or dizziness after sun exposure
- Shortness of breath or chest tightness
- Red, swollen calves or ankles (a potential sign of clotting)
- Sudden mood swings or irritability
Sarah Jefferies adds:
“If a gym-goer or colleague seems light-headed or complains of chest discomfort — especially in the heat, first aiders need to know it could be linked to hormones. Sit them down, offer water, and call 999 if symptoms escalate.”
She’s also urging men to avoid combining testosterone use with alcohol, energy drinks, or fat-burning supplements in summer:
“All of these add extra strain. Your body’s already trying to cool itself — TRT makes that job harder.”
