Context :

Aims : The main goal of this study is to carry out a spatially resolved investigation of the warm interstellar medium ( ISM ) in the extremely metal-poor Blue Compact Dwarf ( BCD ) galaxy HS 2236+1344 .
Special emphasis is laid on the analysis of the spatial distribution of chemical abundances , emission-line ratios and kinematics of the ISM , and to the recent star-forming ( SF ) activity in this galaxy .

Methods : This study is based on optical integral field unit spectroscopy data from Gemini Multi-Object Spectrograph ( GMOS ) at the Gemini North telescope and archival Sloan Digital Sky Survey ( SDSS ) images .
The galaxy has been observed at medium spectral resolution ( R \sim 4000 ) over the spectral range from \sim 4300 \AA to 6800 \AA .
The data were obtained in two different positions across the galaxy , obtaining a total 4″ \times 8″ field which encompasses most of its ISM .

Results : Emission-line maps and broad-band images obtained in this study indicate that HS 2236+1344 hosts three Giant H ii regions ( GH ii Rs ) .
Our data also reveal some faint curved features in the BCD periphery that might be due to tidal perturbations or expanding ionized-gas shells .
The ISM velocity field shows systematic gradients along the major axis of the BCD , with its south-eastern and north-western half differing by \sim 80 km/s in their recessional velocity .
The H \alpha and H \beta equivalent width distribution in the central part of HS 2236+1344 is consistent with a very young ( \sim 3 Myr ) burst .
Our surface photometry analysis indicates that the ongoing starburst provides \sim 50 % of the total optical emission , similar to other BCDs .
It also reveals an underlying lower-surface brightness component with moderately red colors , which suggest that the galaxy has undergone previous star formation .
We derive an integrated oxygen abundance of 12+log ( O/H ) =7.53 \pm 0.06 and a nitrogen-to-oxygen ratio of log ( N/O ) =-1.57 \pm 0.19 .
Our results are consistent , within the uncertainties , with a homogeneous distribution of oxygen and nitrogen within the ISM of the galaxy .
The high-ionization He ii \lambda 4686 emission line is detected only in the central part of HS 2236+1344 .
Similar to many BCDs with He ii \lambda 4686 emission , HS 2236+1344 shows no Wolf-Rayet ( WR ) bump .

Conclusions :