\documentclass[phdthesis,en]{estgleiria}

\usepackage{carreira_phd_thesis}
\usepackage{lipsum}
\usepackage{showframe}
\usepackage{balance}

% \usepackage[active,tightpage]{preview}
% \PreviewEnvironment{tikzpicture}

\begin{document}

\begin{figure}[t]
\centering
<>
\caption{This is the caption.}
\end{figure}

\balance
\lipsum[1-2]

\end{document}