Hot Weather and Mounjaro: What You Need to Know
Hot weather & Mounjaro; What’s the big deal? British summers are nothing if not unpredictable. One week it’s grey skies and drizzle, the next we’re all sticking to our chairs, sleeping with the windows wide open, and wondering if it’s too early to panic-buy a fan.
If you’re taking Mounjaro, though, you might notice the heat affects you a little differently. You might not sweat like everyone else. You might not even feel hot at all. But that doesn’t mean your body isn’t working hard to stay cool, and if you’re not careful, it could leave you dehydrated or run down.
Here’s why hot weather matters more when you’re on Mounjaro, and how to look after yourself properly during a heatwave.
Feeling Cold on Mounjaro in Hot Weather? You’re Not Alone
It’s one of the stranger quirks of being on Mounjaro: some people say they feel cold all the time—even when it’s warm out. So while your mates are moaning about the heat, you might be wrapped in a jumper wondering if there’s something wrong with you.
There’s actually a reason for this. Clinical studies have shown that Mounjaro can affect how your body regulates temperature. It may slow down your metabolism or change how blood flows near your skin, which can lead to that ‘cold all the time’ feeling (even if your core body temperature is fine).
But here’s the important bit: just because you don’t feel hot doesn’t mean your body isn’t overheating. If you’re not sweating or don’t feel thirsty, it’s still possible to become dehydrated—especially when the temperature climbs.
Why You Need to Drink More Water on Mounjaro in Hot Weather
You’ve probably heard the advice: drink plenty of water, especially when it’s hot. But if you’re on Mounjaro, this becomes even more important.
Mounjaro can cause side effects like nausea, reduced appetite, and sometimes just a general feeling of “meh” around food and drink. That might mean you’re eating and drinking less than usual without even realising. Combine that with the fluid you lose through sweat in hot weather, and it’s easy to see how dehydration can sneak up on you.
Even without much activity, your body works hard to keep you cool in the heat. And it needs water to do that properly.
So what’s enough? While the usual recommendation is around 2 litres a day, if it’s hot—or you’re feeling a bit off—it’s a good idea to aim for a bit more. Keep a bottle with you, take regular sips, and don’t wait until you’re thirsty. Thirst is often a late sign that your body’s already behind.
Can Mounjaro Make You More Sensitive to the Sun?
It’s not an officially listed side effect, but quite a few people have said they’ve noticed they’re more prone to sunburn or skin sensitivity since starting Mounjaro. Whether from weight loss, hormones, or skin changes, the cause isn’t clear, but it’s wise to stay cautious.
Sun safety is always important, but especially so if your body’s a bit more vulnerable than usual. If you’re out and about, slap on the SPF (factor 30 or higher), wear light layers, and try to avoid being in direct sun during the hottest part of the day, usually from late morning to mid-afternoon.
It’s not about hiding indoors all summer, but a little extra care can go a long way.
Looking After Yourself on Mounjaro During a Heatwave
Living well on Mounjaro means paying attention to the little signals your body gives you. In a heatwave, that becomes even more important.
Don’t wait until you’re dizzy, light-headed, or have a cracking headache to realise you’re dehydrated. Try to build water into your day, just like you would meals. If you’re feeling tired or foggy, or your skin seems more sensitive than usual, give yourself permission to slow down and rest.
Also, don’t ignore persistent nausea or gut discomfort. These are known side effects of Mounjaro, and in the heat, they can hit harder. Speak to your GP or pharmacist if you’re unsure how to manage them safely.
Final Thoughts: Mounjaro, Hot Weather
British heatwaves might not come often, but when they do, they hit hard, and for those taking Mounjaro, the effects can be a bit more intense than you’d expect.
The key takeaway? Don’t wait until you feel hot, thirsty, or unwell. Sip water throughout the day, take sun safety seriously, and help your body stay cool in the summer heat.
Being on Mounjaro is a journey, but with care, you can stay safe, hydrated, and enjoy summer fully.
Disclaimer
This article is for general information purposes only and does not constitute medical advice. If you have any concerns about how hot weather and medication may affect your health, especially if you’re taking Mounjaro, please speak to NHS 111, your GP or healthcare provider.