how hot is too hot when exercising?

[Walnut8]

I'm really confused about this. I've been walking every day for 40 mins on a treadmill at a brisk pace through my first trimester and get moderately sweaty & pink faced. The gym I do this in is a small gym in my apartment block with only an extractor type fan (but when I first enter doesn't feel stuffy or hot).

Although I don't feel dizzy or anything, and I'm not exercising to the point where I'm anywhere near gasping for breath, I'm paranoid that I'm getting too hot. Am I being ridiculous? How hot is too hot? And how can you exercise without getting hot and sweaty? Sorry for all the questions, I have been trying to find an answer to this but the advice just seems to be "don't overheat".

Funny - I was thinking about this just yesterday. You know, the "health experts" talk about keeping your temp and heart-rate down.

i) if you're an exercise-addict and not a complete numpty you'll dream plenty and look at your salts levels anyway right?

ii) heart-rate - now this is the one which intrigues me:
They tell you to keep your HR < 145 because allegedly after that less O2 is carried by your haemoglobin to be delivered to the baby. However, if you are an athletic exercise-freak lunatic (i.e., moi) then surely my blood is already optimised for O2 carriage throughout my body - if it weren't I'd keel over! (Seriously, regular exercise increases your oxygen carrying capactiy... I think they're preaching to the choir here)

When I run my HR goes up to around 165 - if I keep it below 145 then I don't "feel" like I'm working out.

Any other thoughts about this ladies?

I asked my MW about this (the HR < 145) the other day, as I too got a bit concered while on the cross trainer and she said "Oh, don't worry about that". Basically, as long as you feel well while exercising (no pain, no dizziness or difficulty breathing also no bleeding... although that might be a tad difficult to see during the actual exercise) you should be fine. Listen to your body... this was the advice I was given.

Walnut8 to minimise the riskt of overheating (although I don't know what is actually considered "too hot") advice I have been given have been to drinkt plenty of water and to wear loose clothes.

I have not heard of anybody having risked the health of their baby due to exercise but that is not to say it never happens I suppose...

I suspect it's hard to overheat as long as you are well-hydrated and only push yourself as hard as feels comfortable.
Mind, it is easy to get too dehydrated in pregnancy, I heard of a pregnant woman getting heatstroke just sitting in a hot car for an hour (in Texas in summer) without a drink.

Valllmo That's great thank you!

You're right too - I've never heard of anyone risking their baby's health due to exercise!