Okey, that is not correct.
Change to something like this.
Class temperatuur
Shared Event GetTemp() RaiseEvent Every 1 Minutes
LedGreen = True
Dim TempC As Float = TempSensor.GetTemp()
Dim TempF As Float = TempSensor.ToFarenheit(TempC)
Dim tempstring As String = TempC.ToString()
If TempC > 25.0 Then
LedRed = True
Else
LedRed = False
End If
LedGreen = False
Lplan.IFTTT("d8cAVjNUjBr1S9aUB70Wvc", "temperatuur", tempstring, "", "")
End Event
End Class