new milk or the heat?

[poweredbyjaffacakes]

My twins are now 7 months and I have switched their formula to the follow on milk (were previously on bf & 1st stage formula).
I switched over the last couple of weeks, just as the weather warmed up.

For the last few days they have both had numerous dirty nappies which vary between soft & runny. It was normally 1 or 2 a day but this morning already I've changed 5 between the both of them.
They both seem fine -no temp, still eating/sleeping/playing like normal, although my dts has seemed like he's started teething yesterday.
I've had several comments that its due to the heat (none from anyone in the medical profession though!). Could it be this or more likely the formula? Will take them to GP if it continues.

[LimaCharlie]

Heat did affect my DC as babies - IIWY I would be tempted to go back to the other milk just to ride the storm of the heatwave period and poss teething and then change back again afterwards.